Style and Format
Manuscript files can be in the following formats: DOC, DOCX, or RTF. Microsoft Word documents should not be locked or protected.
LaTeX manuscripts must be submitted as PDFs. Read the LaTeX guidelines.
|Manuscripts can be any length. There are no restrictions on word count, number of figures, or amount of supporting information. |
Use a standard font size and any standard font, except for the font named “Symbol”. To add symbols to the manuscript, use the Insert → Symbol function in your word processor or paste in the appropriate Unicode character.
|Limit manuscript sections and sub-sections to 3 heading levels. Make sure heading levels are clearly indicated in the manuscript text.|
Layout and spacing
Manuscript text should be double-spaced.
Do not format text in multiple columns.
Page and line numbers
|Include page numbers and line numbers in the manuscript file. Use continuous line numbers (do not restart the numbering on each page).|
|Footnotes are not permitted. If your manuscript contains footnotes, move the information into the main text or the reference list, depending on the content.|
Manuscripts must be submitted in English.
You may submit translations of the manuscript or abstract as supporting information. Read the supporting information guidelines.
Define abbreviations upon first appearance in the text.
Do not use non-standard abbreviations unless they appear at least three times in the text.
Keep abbreviations to a minimum.
PLOS uses “Vancouver” style, as outlined in the ICMJE sample references.
See reference formatting examples and additional instructions below.
We recommend using MathType for display and inline equations, as it will provide the most reliable outcome. If this is not possible, Equation Editor or Microsoft's Insert→Equation function is acceptable.
Avoid using MathType, Equation Editor, or the Insert→Equation function to insert single variables (e.g., “a² + b² = c²”), Greek or other symbols (e.g., β, Δ, or ′ [prime]), or mathematical operators (e.g., x, ≥, or ±) in running text. Wherever possible, insert single symbols as normal text with the correct Unicode (hex) values.
Do not use MathType, Equation Editor, or the Insert→Equation function for only a portion of an equation. Rather, ensure that the entire equation is included. Equations should not contain a mix of different equation tools. Avoid “hybrid” inline or display equations, in which part is text and part is MathType, or part is MathType and part is Equation Editor.
Use correct and established nomenclature wherever possible.
Prior to submission, authors who believe their manuscripts would benefit from professional editing are encouraged to use language-editing and copyediting services. Obtaining this service is the responsibility of the author, and should be done before initial submission. These services can be found on the web using search terms like “scientific editing service” or “manuscript editing service.”
Submissions are not copyedited before publication.
Submissions that do not meet the PLOS ONE publication criterion for language standards may be rejected.
Manuscripts should be organized as follows. Instructions for each element appear below the list.
The following elements are required, in order:
The following elements can be renamed as needed and presented in any order:
The following elements are required, in order:
Viewing Figures and Supporting Information in the compiled submission PDF
The compiled submission PDF includes low-resolution preview images of the figures after the reference list. The function of these previews is to allow you to download the entire submission as quickly as possible. Click the link at the top of each preview page to download a high-resolution version of each figure. Links to download Supporting Information files are also available after the reference list.
Parts of a Submission
Include a full title and a short title for the manuscript.
|Full title||250 characters||Specific, descriptive, concise, and comprehensible to readers outside the field|
Impact of cigarette smoke exposure on innate immunity: A Caenorhabditis elegans model
Solar drinking water disinfection (SODIS) to reduce childhood diarrhoea in rural Bolivia: A cluster-randomized, controlled trial
|Short title||100 characters||State the topic of the study|
Cigarette smoke exposure and innate immunitySODIS and childhood diarrhoea
Titles should be written in sentence case (only the first word of the text, proper nouns, and genus names are capitalized). Avoid specialist abbreviations if possible. For clinical trials, systematic reviews, or meta-analyses, the subtitle should include the study design.
All authors must meet the criteria for authorship as outlined in the authorship policy. Those who contributed to the work but do not meet the criteria for authorship can be mentioned in the Acknowledgments. Read more about Acknowledgments.
The corresponding author must provide an ORCID iD at the time of submission by entering it in the user profile in the submission system. Read more about ORCID.
Author names and affiliations
Enter author names on the title page of the manuscript and in the online submission system.
On the title page, write author names in the following order:
- First name (or initials, if used)
- Middle name (or initials, if used)
- Last name (surname, family name)
Each author on the list must have an affiliation. The affiliation includes department, university, or organizational affiliation and its location, including city, state/province (if applicable), and country. Authors have the option to include a current address in addition to the address of their affiliation at the time of the study. The current address should be listed in the byline and clearly labeled “current address.” At a minimum, the address must include the author’s current institution, city, and country.
If an author has multiple affiliations, enter all affiliations on the title page only. In the submission system, enter only the preferred or primary affiliation. Author affiliations will be listed in the typeset PDF article in the same order that authors are listed in the submission.
Author names will be published exactly as they appear in the manuscript file. Please double-check the information carefully to make sure it is correct.
The submitting author is automatically designated as the corresponding author in the submission system. The corresponding author is the primary contact for the journal office and the only author able to view or change the manuscript while it is under editorial consideration.
The corresponding author role may be transferred to another coauthor. However, note that transferring the corresponding author role also transfers access to the manuscript. (To designate a new corresponding author while the manuscript is still under consideration, watch the video tutorial below.)
Only one corresponding author can be designated in the submission system, but this does not restrict the number of corresponding authors that may be listed on the article in the event of publication. Whoever is designated as a corresponding author on the title page of the manuscript file will be listed as such upon publication. Include an email address for each corresponding author listed on the title page of the manuscript.
How to select a new corresponding author in Editorial Manager
Consortia and group authorship
If a manuscript is submitted on behalf of a consortium or group, include the consortium or group name in the author list, and provide the full list of consortium or group members in the Acknowledgments section. The consortium or group name should be listed in the manuscript file only, and not included in the online submission form. Please be aware that as of October 2016, the National Library of Medicine’s (NLM) policy has changed and PubMed will only index individuals and the names of consortia or group authors listed in the author byline itself. Individual consortium or group author members need to be listed in the author byline in order to be indexed, and if included in the byline, must qualify for authorship according to our criteria.
Read about the group authorship policy.
Provide at minimum one contribution for each author in the submission system. Use the CRediT taxonomy to describe each contribution. Read the policy and the full list of roles.
Contributions will be published with the final article, and they should accurately reflect contributions to the work. The submitting author is responsible for completing this information at submission, and we expect that all authors will have reviewed, discussed, and agreed to their individual contributions ahead of this time.
PLOS ONE will contact all authors by email at submission to ensure that they are aware of the submission.
Upload a cover letter as a separate file in the online system. The length limit is 1 page.
The cover letter should include the following information:
- Summarize the study’s contribution to the scientific literature
- Relate the study to previously published work
- Specify the type of article (for example, research article, systematic review, meta-analysis, clinical trial)
- Describe any prior interactions with PLOS regarding the submitted manuscript
- Suggest appropriate Academic Editors to handle your manuscript (see the full list of Academic Editors)
- List any opposed reviewers
IMPORTANT: Do not include requests to reduce or waive publication fees in the cover letter. This information will be entered separately in the online submission system.Read about publication fee assistance.
The title, authors, and affiliations should all be included on a title page as the first page of the manuscript file.
The Abstract comes after the title page in the manuscript file. The abstract text is also entered in a separate field in the submission system.
The Abstract should:
- Describe the main objective(s) of the study
- Explain how the study was done, including any model organisms used, without methodological detail
- Summarize the most important results and their significance
- Not exceed 300 words
Abstracts should not include:
- Abbreviations, if possible
The introduction should:
- Provide background that puts the manuscript into context and allows readers outside the field to understand the purpose and significance of the study
- Define the problem addressed and why it is important
- Include a brief review of the key literature
- Note any relevant controversies or disagreements in the field
- Conclude with a brief statement of the overall aim of the work and a comment about whether that aim was achieved
Materials and Methods
The Materials and Methods section should provide enough detail to allow suitably skilled investigators to fully replicate your study. Specific information and/or protocols for new methods should be included in detail. If materials, methods, and protocols are well established, authors may cite articles where those protocols are described in detail, but the submission should include sufficient information to be understood independent of these references.
Protocol documents for clinical trials, observational studies, and other non-laboratory investigations may be uploaded as supporting information. Read the supporting information guidelines for formatting instructions. We recommend depositing laboratory protocols at protocols.io. Read detailed instructions for depositing and sharing your laboratory protocols.
Human or animal subjects and/or tissue or field sampling
Methods sections describing research using human or animal subjects and/or tissue or field sampling must include required ethics statements. See the reporting guidelines for human research, clinical trials, animal research, and observational and field studies for more information.
PLOS journals require authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception.
Large data sets, including raw data, may be deposited in an appropriate public repository. See our list of recommended repositories.
For smaller data sets and certain data types, authors may provide their data within supporting information files accompanying the manuscript. Authors should take care to maximize the accessibility and reusability of the data by selecting a file format from which data can be efficiently extracted (for example, spreadsheets or flat files should be provided rather than PDFs when providing tabulated data).
For more information on how best to provide data, read our policy on data availability. PLOS does not accept references to “data not shown.”
Methods sections describing research using cell lines must state the origin of the cell lines used. See the reporting guidelines for cell line research for more information.
To enhance the reproducibility of your results, we recommend and encourage you to deposit laboratory protocols in protocols.io, where protocols can be assigned their own persistent digital object identifiers (DOIs).
To include a link to a protocol in your article:
- Describe your step-by-step protocol on protocols.io
- Select Get DOI to issue your protocol a persistent digital object identifier (DOI)
- Include the DOI link in the Methods section of your manuscript using the following format provided by protocols.io: http://dx.doi.org/10.17504/protocols.io.[PROTOCOL DOI]
At this stage, your protocol is only visible to those with the link. This allows editors and reviewers to consult your protocol when evaluating the manuscript. You can make your protocols public at any time by selecting Publish on the protocols.io site. Any referenced protocol(s) will automatically be made public when your article is published.
New taxon names
Methods sections of manuscripts adding new taxon names to the literature must follow the reporting guidelines below for a new zoological taxon, botanical taxon, or fungal taxon.
Results, Discussion, Conclusions
These sections may all be separate, or may be combined to create a mixed Results/Discussion section (commonly labeled “Results and Discussion”) or a mixed Discussion/Conclusions section (commonly labeled “Discussion”). These sections may be further divided into subsections, each with a concise subheading, as appropriate. These sections have no word limit, but the language should be clear and concise.
Together, these sections should describe the results of the experiments, the interpretation of these results, and the conclusions that can be drawn.
Authors should explain how the results relate to the hypothesis presented as the basis of the study and provide a succinct explanation of the implications of the findings, particularly in relation to previous related studies and potential future directions for research.
PLOS ONE editorial decisions do not rely on perceived significance or impact, so authors should avoid overstating their conclusions. See the PLOS ONE Criteria for Publication for more information.
Those who contributed to the work but do not meet our authorship criteria should be listed in the Acknowledgments with a description of the contribution.
Authors are responsible for ensuring that anyone named in the Acknowledgments agrees to be named.
Do not include funding sources in the Acknowledgments or anywhere else in the manuscript file. Funding information should only be entered in the financial disclosure section of the submission system.
Any and all available works can be cited in the reference list. Acceptable sources include:
- Published or accepted manuscripts
- Manuscripts on preprint servers, providing the manuscript has a citable DOI or arXiv URL. Read the Preprint Policy.
Do not cite the following sources in the reference list:
- Unavailable and unpublished work, including manuscripts that have been submitted but not yet accepted (e.g., “unpublished work,” “data not shown”). Instead, include those data as supplementary material or deposit the data in a publicly available database.
- Personal communications (these should be supported by a letter from the relevant authors but not included in the reference list)
References are listed at the end of the manuscript and numbered in the order that they appear in the text. In the text, cite the reference number in square brackets (e.g., “We used the techniques developed by our colleagues  to analyze the data”). PLOS uses the numbered citation (citation-sequence) method and first six authors, et al.
Do not include citations in abstracts or author summaries.
Make sure the parts of the manuscript are in the correct order before ordering the citations.
Because all references will be linked electronically as much as possible to the papers they cite, proper formatting of the references is crucial.
PLOS uses the reference style outlined by the International Committee of Medical Journal Editors (ICMJE), also referred to as the “Vancouver” style. Example formats are listed below. Additional examples are in the ICMJE sample references.
A reference management tool, EndNote, offers a current style file that can assist you with the formatting of your references. If you have problems with any reference management program, please contact the source company's technical support.
Journal name abbreviations should be those found in the National Center for Biotechnology Information (NCBI) databases.
Hou WR, Hou YL, Wu GF, Song Y, Su XL, Sun B, et al. cDNA, genomic sequence cloning and overexpression of ribosomal protein gene L9 (rpL9) of the giant panda (Ailuropoda melanoleuca). Genet Mol Res. 2011;10: 1576-1588.
Devaraju P, Gulati R, Antony PT, Mithun CB, Negi VS. Susceptibility to SLE in South Indian Tamils may be influenced by genetic selection pressure on TLR2 and TLR9 genes. Mol Immunol. 2014 Nov 22. pii: S0161-5890(14)00313-7. doi: 10.1016/j.molimm.2014.11.005.
Note: A DOI number for the full-text article is acceptable as an alternative to or in addition to traditional volume and page numbers. When providing a DOI, adhere to the format in the example above with both the label and full DOI included at the end of the reference (doi: 10.1016/j.molimm.2014.11.005). Do not provide a shortened DOI or the URL.
|Accepted, unpublished articles||Same as published articles, but substitute “Forthcoming” for page numbers or DOI.|
Huynen MMTE, Martens P, Hilderlink HBM. The health impacts of globalisation: a conceptual framework. Global Health. 2005;1: 14. Available from: http://www.globalizationandhealth.com/content/1/1/14
Bates B. Bargaining for life: A social history of tuberculosis. 1st ed. Philadelphia: University of Pennsylvania Press; 1992.
|Book chapters||Hansen B. New York City epidemics and history for the public. In: Harden VA, Risse GB, editors. AIDS and the historian. Bethesda: National Institutes of Health; 1991. pp. 21-28.|
|Deposited articles (preprints, e-prints, or arXiv)||Krick T, Shub DA, Verstraete N, Ferreiro DU, Alonso LG, Shub M, et al. Amino acid metabolism conflicts with protein diversity; 1991. Preprint. Available from: arXiv:1403.3301v1. Cited 17 March 2014.|
|Published media (print or online newspapers and magazine articles)||Fountain H. For Already Vulnerable Penguins, Study Finds Climate Change Is Another Danger. The New York Times. 29 Jan 2014. Available from: http://www.nytimes.com/2014/01/30/science/earth/climate-change-taking-toll-on-penguins-study-finds.html Cited 17 March 2014.|
|New media (blogs, web sites, or other written works)||Allen L. Announcing PLOS Blogs. 2010 Sep 1 [cited 17 March 2014]. In: PLOS Blogs [Internet]. San Francisco: PLOS 2006 - . [about 2 screens]. Available from: http://blogs.plos.org/plos/2010/09/announcing-plos-blogs/.|
|Masters' theses or doctoral dissertations||Wells A. Exploring the development of the independent, electronic, scholarly journal. M.Sc. Thesis, The University of Sheffield. 1999. Available from: http://cumincad.scix.net/cgi-bin/works/Show?2e09|
|Databases and repositories (Figshare, arXiv)||Roberts SB. QPX Genome Browser Feature Tracks; 2013 [cited 2013 Oct 5]. Database: figshare [Internet]. Available from: http://figshare.com/articles/QPX_Genome_Browser_Feature_Tracks/701214|
|Multimedia (videos, movies, or TV shows)||Hitchcock A, producer and director. Rear Window [Film]; 1954. Los Angeles: MGM.|
Authors can submit essential supporting files and multimedia files along with their manuscripts. All supporting information will be subject to peer review. All file types can be submitted, but files must be smaller than 10 MB in size.
Authors may use almost any description as the item name for a supporting information file as long as it contains an “S” and number. For example, “S1 Appendix” and “S2 Appendix,” “S1 Table” and “S2 Table,” and so forth.
Supporting information files are published exactly as provided, and are not copyedited.
Supporting information captions
List supporting information captions at the end of the manuscript file. Do not submit captions in a separate file.
The file number and name are required in a caption, and we highly recommend including a one-line title as well. You may also include a legend in your caption, but it is not required.
S1 Text. Title is strongly recommended. Legend is optional.
We recommend that you cite supporting information in the manuscript text, but this is not a requirement. If you cite supporting information in the text, citations do not need to be in numerical order.
Read the supporting information guidelines for more details about submitting supporting information and multimedia files.
Figures and Tables
Do not include figures in the main manuscript file. Each figure must be prepared and submitted as an individual file.
Cite figures in ascending numeric order upon first appearance in the manuscript file.
Read the guidelines for figures.
Figure captions must be inserted in the text of the manuscript, immediately following the paragraph in which the figure is first cited (read order). Do not include captions as part of the figure files themselves or submit them in a separate document.
At a minimum, include the following in your figure captions:
- A figure label with Arabic numerals, and “Figure” abbreviated to “Fig” (e.g. Fig 1, Fig 2, Fig 3, etc). Match the label of your figure with the name of the file uploaded at submission (e.g. a figure citation of “Fig 1” must refer to a figure file named “Fig1.tif”).
- A concise, descriptive title
The caption may also include a legend as needed.
Read more about figure captions.
Cite tables in ascending numeric order upon first appearance in the manuscript file.
Place each table in your manuscript file directly after the paragraph in which it is first cited (read order). Do not submit your tables in separate files.
Tables require a label (e.g., “Table 1”) and brief descriptive title to be placed above the table. Place legends, footnotes, and other text below the table.
Read the guidelines for tables.
All data and related metadata underlying the findings reported in a submitted manuscript should be deposited in an appropriate public repository, unless already provided as part of the submitted article.
Read our policy on data availability.
Repositories may be either subject-specific (where these exist) and accept specific types of structured data, or generalist repositories that accept multiple data types. We recommend that authors select repositories appropriate to their field. Repositories may be subject-specific (e.g., GenBank for sequences and PDB for structures), general, or institutional, as long as DOIs or accession numbers are provided and the data are at least as open as CC BY. Authors are encouraged to select repositories that meet accepted criteria as trustworthy digital repositories, such as criteria of the Centre for Research Libraries or Data Seal of Approval. Large, international databases are more likely to persist than small, local ones.
See our list of recommended repositories.
To support data sharing and author compliance of the PLOS data policy, we have integrated our submission process with a select set of data repositories. The list is neither representative nor exhaustive of the suitable repositories available to authors. Current repository integration partners include Dryad and FlowRepository. Please contact firstname.lastname@example.org to make recommendations for further partnerships.
Instructions for PLOS submissions with data deposited in an integration partner repository:
- Deposit data in the integrated repository of choice.
- Once deposition is final and complete, the repository will provide you with a dataset DOI (provisional) and private URL for reviewers to gain access to the data.
- Enter the given data DOI into the full Data Availability Statement, which is requested in the Additional Information section of the PLOS submission form. Then provide the URL passcode in the Attach Files section.
If you have any questions, please email us.
All appropriate data sets, images, and information should be deposited in an appropriate public repository. See our list of recommended repositories.
Accession numbers (and version numbers, if appropriate) should be provided in the Data Availability Statement. Accession numbers or a citation to the DOI should also be provided when the data set is mentioned within the manuscript.
In some cases authors may not be able to obtain accession numbers of DOIs until the manuscript is accepted; in these cases, the authors must provide these numbers at acceptance. In all other cases, these numbers must be provided at submission.
As much as possible, please provide accession numbers or identifiers for all entities such as genes, proteins, mutants, diseases, etc., for which there is an entry in a public database, for example:
Identifiers should be provided in parentheses after the entity on first use.
You can choose to upload a “Striking Image” that we may use to represent your article online in places like the journal homepage or in search results.
The striking image must be derived from a figure or supporting information file from the submission, i.e., a cropped portion of an image or the entire image. Striking images should ideally be high resolution, eye-catching, single panel images, and should ideally avoid containing added details such as text, scale bars, and arrows.
If no striking image is uploaded, we will designate a figure from the submission as the striking image.
Additional Information Requested at Submission
This information should not be in your manuscript file; you will provide it via our submission system.
This information will be published with the final manuscript, if accepted, so please make sure that this is accurate and as detailed as possible. You should not include this information in your manuscript file, but it is important to gather it prior to submission, because your financial disclosure statement cannot be changed after initial submission.
Your statement should include relevant grant numbers and the URL of any funder's web site. Please also state whether any individuals employed or contracted by the funders (other than the named authors) played any role in: study design, data collection and analysis, decision to publish, or preparation of the manuscript. If so, please name the individual and describe their role.
Read our policy on disclosure of funding sources.
This information should not be in your manuscript file; you will provide it via our submission system.
All potential competing interests must be declared in full. If the submission is related to any patents, patent applications, or products in development or for market, these details, including patent numbers and titles, must be disclosed in full.
Read our policy on competing interests.
Manuscripts disputing published work
For manuscripts disputing previously published work, it is PLOS ONE policy to invite a signed review by the disputed author during the peer review process. This procedure is aimed at ensuring a thorough, transparent, and productive review process.
If the disputed author chooses to submit a review, it must be returned in a timely fashion and contain a full declaration of all competing interests. The Academic Editor will consider any such reviews in light of the competing interest.
Authors submitting manuscripts disputing previous work should explain the relationship between the manuscripts in their cover letter, and will be required to confirm that they accept the conditions of this review policy before the manuscript is considered further.
Upon submission, authors must confirm that the manuscript, or any related manuscript, is not currently under consideration or accepted elsewhere. If related work has been submitted to PLOS ONE or elsewhere, authors must include a copy with the submitted article. Reviewers will be asked to comment on the overlap between related submissions.
We strongly discourage the unnecessary division of related work into separate manuscripts, and we will not consider manuscripts that are divided into “parts.” Each submission to PLOS ONE must be written as an independent unit and should not rely on any work that has not already been accepted for publication. If related manuscripts are submitted to PLOS ONE, the authors may be advised to combine them into a single manuscript at the editor's discretion.
PLOS does support authors who wish to share their work early and receive feedback before formal peer review. Deposition of manuscripts with preprint servers does not impact consideration of the manuscript at any PLOS journal.
Guidelines for Specific Study Types
Human subjects research
All research involving human participants must have been approved by the authors’ Institutional Review Board (IRB) or by equivalent ethics committee(s), and must have been conducted according to the principles expressed in the Declaration of Helsinki. Authors should be able to submit, upon request, a statement from the IRB or ethics committee indicating approval of the research. We reserve the right to reject work that we believe has not been conducted to a high ethical standard, even when formal approval has been obtained.
Subjects must have been properly instructed and have indicated that they consent to participate by signing the appropriate informed consent paperwork. Authors may be asked to submit a blank, sample copy of a subject consent form. If consent was verbal instead of written, or if consent could not be obtained, the authors must explain the reason in the manuscript, and the use of verbal consent or the lack of consent must have been approved by the IRB or ethics committee.
All efforts should be made to protect patient privacy and anonymity. Identifying information, including photos, should not be included in the manuscript unless the information is crucial and the individual has provided written consent by completing the Consent Form for Publication in a PLOS Journal (PDF). Download additional translations of the form from the Downloads and Translations page. More information about patient privacy, anonymity, and informed consent can be found in the International Committee of Medical Journal Editors (ICMJE) Privacy and Confidentiality guidelines.
Manuscripts should conform to the following reporting guidelines:
- Studies of diagnostic accuracy: STARD
- Observational studies: STROBE
- Microarray experiments: MIAME
- Other types of health-related research: Consult the EQUATOR web site for appropriate reporting guidelines
Methods sections of papers on research using human subjects or samples must include ethics statements that specify:
- The name of the approving institutional review board or equivalent committee(s). If approval was not obtained, the authors must provide a detailed statement explaining why it was not needed
- Whether informed consent was written or oral. If informed consent was oral, it must be stated in the manuscript:
- Why written consent could not be obtained
- That the Institutional Review Board (IRB) approved use of oral consent
- How oral consent was documented
For studies involving humans categorized by race/ethnicity, age, disease/disabilities, religion, sex/gender, sexual orientation, or other socially constructed groupings, authors should:
- Explicitly describe their methods of categorizing human populations
- Define categories in as much detail as the study protocol allows
- Justify their choices of definitions and categories, including for example whether any rules of human categorization were required by their funding agency
- Explain whether (and if so, how) they controlled for confounding variables such as socioeconomic status, nutrition, environmental exposures, or similar factors in their analysis
In addition, outmoded terms and potentially stigmatizing labels should be changed to more current, acceptable terminology. Examples: “Caucasian” should be changed to “white” or “of [Western] European descent” (as appropriate); “cancer victims” should be changed to “patients with cancer.”
For papers that include identifying, or potentially identifying, information, authors must download the Consent Form for Publication in a PLOS Journal, which the individual, parent, or guardian must sign once they have read the paper and been informed about the terms of PLOS open-access license. The signed consent form should not be submitted with the manuscript, but authors should securely file it in the individual's case notes and the methods section of the manuscript should explicitly state that consent authorization for publication is on file, using wording like:
The individual in this manuscript has given written informed consent (as outlined in PLOS consent form) to publish these case details.
For more information about PLOS ONE policies regarding human subjects research, see the Publication Criteria and Editorial Policies.
Clinical trials are subject to all policies regarding human research. PLOS ONE follows the World Health Organization's (WHO) definition of a clinical trial:
A clinical trial is any research study that prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects on health outcomes [...] Interventions include but are not restricted to drugs, cells and other biological products, surgical procedures, radiologic procedures, devices, behavioural treatments, process-of-care changes, preventive care, etc.
All clinical trials must be registered in one of the publicly-accessible registries approved by the WHO or ICMJE (International Committee of Medical Journal Editors). Authors must provide the trial registration number. Prior disclosure of results on a clinical trial registry site will not affect consideration for publication. We reserve the right to inform authors' institutions or ethics committees, and to reject the manuscript, if we become aware of unregistered trials.
PLOS ONE supports prospective trial registration (i.e. before participant recruitment has begun) as recommended by the ICMJE's clinical trial registration policy. Where trials were not publicly registered before participant recruitment began, authors must:
- Register all related clinical trials and confirm they have done so in the Methods section
- Explain in the Methods the reason for failing to register before participant recruitment
Clinical trials must be reported according to the relevant reporting guidelines, i.e. CONSORT for randomized controlled trials, TREND for non-randomized trials, and other specialized guidelines as appropriate. The intervention should be described according to the requirements of the TIDieR checklist and guide. Submissions must also include the study protocol as supporting information, which will be published with the manuscript if accepted.
Authors of manuscripts describing the results of clinical trials must adhere to the CONSORT reporting guidelines appropriate to their trial design, available on the CONSORT Statement web site. Before the paper can enter peer review, authors must:
- Provide the registry name and number in the methods section of the manuscript
- Provide a copy of the trial protocol as approved by the ethics committee and a completed CONSORT checklist as supporting information (which will be published alongside the paper, if accepted). This should be named S1 CONSORT Checklist.
- Include the CONSORT flow diagram as the manuscript's “Fig 1”
Any deviation from the trial protocol must be explained in the paper. Authors must explicitly discuss informed consent in their paper, and we reserve the right to ask for a copy of the patient consent form.
The methods section must include the name of the registry, the registry number, and the URL of your trial in the registry database for each location in which the trial is registered.
All research involving vertebrates or cephalopods must have approval from the authors' Institutional Animal Care and Use Committee (IACUC) or equivalent ethics committee(s), and must have been conducted according to applicable national and international guidelines. Approval must be received prior to beginning research.
Manuscripts reporting animal research must state in the Methods section:
- The full name of the relevant ethics committee that approved the work, and the associated permit number(s).
- Where ethical approval is not required, the manuscript should include a clear statement of this and the reason why. Provide any relevant regulations under which the study is exempt from the requirement for approval.
- Relevant details of steps taken to ameliorate animal suffering.
This study was carried out in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. The protocol was approved by the Committee on the Ethics of Animal Experiments of the University of Minnesota (Protocol Number: 27-2956). All surgery was performed under sodium pentobarbital anesthesia, and all efforts were made to minimize suffering.
Authors should always state the organism(s) studied in the Abstract. Where the study may be confused as pertaining to clinical research, authors should also state the animal model in the title.
To maximize reproducibility and potential for re-use of data, we encourage authors to follow the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines for all submissions describing laboratory-based animal research and to upload a completed ARRIVE Guidelines Checklist to be published as supporting information.
Manuscripts describing research involving non-human primates must report details of husbandry and animal welfare in accordance with the recommendations of the Weatherall report, The use of non-human primates in research (PDF), including:
- Information about housing, feeding, and environmental enrichment.
- Steps taken to minimize suffering, including use of anesthesia and method of sacrifice, if appropriate.
Random source animals
Manuscripts describing studies that use random source (e.g. Class B dealer-sourced in the USA), shelter, or stray animals will be subject to additional scrutiny and may be rejected if sufficient ethical and scientific justification for the study design is lacking.
Unacceptable euthanasia methods and anesthetic agents
Manuscripts reporting use of a euthanasia method(s) classified as unacceptable by the American Veterinary Medical Association or use of an anesthesia method(s) that is widely prohibited (e.g., chloral hydrate, ether, chloroform) must include at the time of initial submission, scientific justification for use in the specific study design, as well as confirmation of approval for specific use from their animal research ethics committee. These manuscripts may be subject to additional ethics considerations prior to publication.
Manuscripts reporting studies in which death of a regulated animal (vertebrate, cephalopod) is a likely outcome or a planned experimental endpoint, must comprehensively report details of study design, rationale for the approach, and methodology, including consideration of humane endpoints. This applies to research that involves, for instance, assessment of survival, toxicity, longevity, terminal disease, or high rates of incidental mortality.
Definition of a humane endpoint
A humane endpoint is a predefined experimental endpoint at which animals are euthanized when they display early markers associated with death or poor prognosis of quality of life, or specific signs of severe suffering or distress. Humane endpoints are used as an alternative to allowing such conditions to continue or progress to death following the experimental intervention (“death as an endpoint”), or only euthanizing animals at the end of an experiment. Before a study begins, researchers define the practical observations or measurements that will be used during the study to recognize a humane endpoint, based on anticipated clinical, physiological, and behavioral signs. Please see the NC3Rs guidelines for more information. Additional discussion of humane endpoints can be found in this article: Nuno H. Franco, Margarida Correia-Neves, I. Anna S. Olsson (2012) How “Humane” Is Your Endpoint? — Refining the Science-Driven Approach for Termination of Animal Studies of Chronic Infection. PLoS Pathog 8(1): e1002399 doi.org/10.1371/journal.ppat.1002399.
Full details of humane endpoints use must be reported for a study to be reproducible and for the results to be accurately interpreted.
For studies in which death of an animal is an outcome or a planned experimental endpoint, authors should include the following information in the Methods section of the manuscript:
- The specific criteria (i.e. humane endpoints) used to determine when animals should be euthanized.
- The duration of the experiment.
- The numbers of animals used, euthanized, and found dead (if any); the cause of death for all animals.
- How frequently animal health and behavior were monitored.
- All animal welfare considerations taken, including efforts to minimize suffering and distress, use of analgesics or anaesthetics, or special housing conditions.
If humane endpoints were not used, the manuscript should report:
- A scientific justification for the study design, including the reasons why humane endpoints could not be used, and discussion of alternatives that were considered.
- Whether the institutional animal ethics committee specifically reviewed and approved the anticipated mortality in the study design.
Observational and field studies
Methods sections for submissions reporting on any type of field study must include ethics statements that specify:
- Permits and approvals obtained for the work, including the full name of the authority that approved the study; if none were required, authors should explain why
- Whether the land accessed is privately owned or protected
- Whether any protected species were sampled
- Full details of animal husbandry, experimentation, and care/welfare, where relevant
Paleontology and archaeology research
Manuscripts reporting paleontology and archaeology research must include descriptions of methods and specimens in sufficient detail to allow the work to be reproduced. Data sets supporting statistical and phylogenetic analyses should be provided, preferably in a format that allows easy re-use. Read the policy.
Specimen numbers and complete repository information, including museum name and geographic location, are required for publication. Locality information should be provided in the manuscript as legally allowable, or a statement should be included giving details of the availability of such information to qualified researchers.
If permits were required for any aspect of the work, details should be given of all permits that were obtained, including the full name of the issuing authority. This should be accompanied by the following statement:
All necessary permits were obtained for the described study, which complied with all relevant regulations.
If no permits were required, please include the following statement:
No permits were required for the described study, which complied with all relevant regulations.
Manuscripts describing paleontology and archaeology research are subject to the following policies:
- Sharing of data and materials. Any specimen that is erected as a new species, described, or figured must be deposited in an accessible, permanent repository (i.e., public museum or similar institution). If study conclusions depend on specimens that do not fit these criteria, the article will be rejected under PLOS ONE's data availability criterion.
- Ethics. PLOS ONE will not publish research on specimens that were obtained without necessary permission or were illegally exported.
Systematic reviews and meta-analyses
A systematic review paper, as defined by The Cochrane Collaboration, is a review of a clearly formulated question that uses explicit, systematic methods to identify, select, and critically appraise relevant research, and to collect and analyze data from the studies that are included in the review. These reviews differ substantially from narrative-based reviews or synthesis articles. Statistical methods (meta-analysis) may or may not be used to analyze and summarize the results of the included studies.
Reports of systematic reviews and meta-analyses must include a completed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist and flow diagram to accompany the main text. Blank templates are available here:
Authors must also state in their “Methods” section whether a protocol exists for their systematic review, and if so, provide a copy of the protocol as supporting information and provide the registry number in the abstract.
If your article is a systematic review or a meta-analysis you should:
- State this in your cover letter
- Select “Research Article” as your article type when submitting
- Include the PRISMA flow diagram as Fig 1 (required where applicable)
- Include the PRISMA checklist as supporting information
Meta-analysis of genetic association studies
Manuscripts reporting a meta-analysis of genetic association studies must report results of value to the field and should be reported according to the guidelines presented in Systematic Reviews of Genetic Association Studies by Sagoo et al.
On submission, authors will be asked to justify the rationale for the meta-analysis and how it contributes to the base of scientific knowledge in the light of previously published results. Authors will also be asked to complete a checklist (DOCX) outlining information about the justification for the study and the methodology employed. Meta-analyses that replicate published studies will be rejected if the authors do not provide adequate justification.
Personal data from third-party sources
For all studies using personal data from internet-based and other third-party sources (e.g., social media, blogs, other internet sources, mobile phone companies), data must be collected and used according to company/website Terms and Conditions, with appropriate permissions. All data sources must be acknowledged clearly in the Materials and Methods section.
Read our policy on data availability.
In the Ethics Statement, authors should declare any potential risks to individuals or individual privacy, or affirm that in their assessment, the study posed no such risks. In addition, the following Ethics and Data Protection requirements must be met.
For interventional studies, which impact participants’ experiences or data, the study design must have been prospectively approved by an Ethics Committee, and informed consent is required. The Ethics Committee may waive the requirement for approval and/or consent.
For observational studies in which personal experiences and accounts are not manipulated, consultation with an Ethics or Data Protection Committee is recommended. Additional requirements apply in the following circumstances:
- If information used could threaten personal privacy or damage the reputation of individuals whose data are used, an Ethics Committee should be consulted and informed consent obtained or specifically addressed.
- If authors accessed any personal identifying information, an Ethics or Data Protection Committee should oversee data anonymization. If data were anonymized and/or aggregated before access and analysis, informed consent is generally not required.
See our reporting guidelines for human subjects research.
Authors reporting research using cell lines should state when and where they obtained the cells, giving the date and the name of the researcher, cell line repository, or commercial source (company) who provided the cells, as appropriate.
Authors must also include the following information for each cell line:
For de novo (new) cell lines, including those given to the researchers as a gift, authors must follow our policies for human subjects research or animal research, as appropriate. The ethics statement must include:
- Details of institutional review board or ethics committee approval; AND
- For human cells, confirmation of written informed consent from the donor, guardian, or next of kin
For established cell lines, the Methods section should include:
- A reference to the published article that first described the cell line; AND/OR
- The cell line repository or company the cell line was obtained from, the catalogue number, and whether the cell line was obtained directly from the repository/company or from another laboratory
Authors should check established cell lines using the ICLAC Database of Cross-contaminated or Misidentified Cell Lines to confirm they are not misidentified or contaminated. Cell line authentication is recommended – e.g., by karyotyping, isozyme analysis, or short tandem repeats (STR) analysis – and may be required during peer review or after publication.
Blots and gels
Manuscripts reporting results from blots (including Western blots) and electrophoretic gels should follow these guidelines:
- In accordance with our policy on image manipulation, the image should not be adjusted in any way that could affect the scientific information displayed, e.g. by modifying the background or contrast.
- All blots and gels that support results reported in the manuscript should be provided.
- Original uncropped and unadjusted blots and gels, including molecular size markers, should be provided in either the figures or the supplementary files.
- Lanes should not be overcropped around the bands; the image should show most or all of the blot or gel. Any non-specific bands should be shown and an explanation of their nature should be given.
- The image should include all relevant controls, and controls should be run on the same blot or gel as the samples.
- A figure panel should not include composite images of bands originating from different blots or gels. If the figure shows non-adjacent bands from the same blot or gel, this should be clearly denoted by vertical black lines and the figure legend should provide details of how the figure was made.
Manuscripts reporting experiments using antibodies should include the following information:
- The name of each antibody, a description of whether it is monoclonal or polyclonal, and the host species.
- The commercial supplier or source laboratory.
- The catalogue or clone number and, if known, the batch number.
- The antigen(s) used to raise the antibody.
- For established antibodies, a stable public identifier from the Antibody Registry.
The manuscript should also report the following experimental details:
- The final antibody concentration or dilution.
- A reference to the validation study if the antibody was previously validated. If not, provide details of how the authors validated the antibody for the applications and species used.
Related information for authors
Please refer to our downloadable sample files to ensure that your submission meets our formatting requirements:
Many journals require a cover letter and state this in their guidelines for authors (alternatively known as author guidelines, information for authors, guide for authors, guidelines for papers, submission guide, etc.). For some journals, a cover letter is optional or may not be not required, but it’s probably a good idea to include one.
Why do some journals ask for cover letters?
Cover letters can be helpful to journal staff in the following ways.
1. Cover letters that include standard statements required by the journal allow the journal staff to quickly confirm that the authors have (or say they have) followed certain ethical research and publishing practices.
These statements assert that the authors followed standard practices, which may include (i) adhering to ethical guidelines for research involving humans (Declaration of Helsinki), involving animals (ARRIVE guidelines), or falling under institutional guidelines; (ii) obtaining ethics approval from institutional review boards or ethics committees; (iii) obtaining informed consent or assent from participants; (iv) complying with authorship criteria (e.g., ICMJE criteria); (v) confirming no duplicate submissions have been made; and (vi) recommending reviewers for your paper, which may include specifying peers that you prefer not be contacted.
2. Cover letters can summarize your manuscript quickly for the journal editor, highlighting your most important findings and their implications to show why your manuscript would be of interest.
Some journals, such as Nature, state that while a cover letter is optional, it provides “an excellent opportunity to briefly discuss the importance of the submitted work and why it is appropriate for the journal.” Some publishers, such as Springer, recommend that you write a cover letter to help “sell” your manuscript to the journal editor.
3. Cover letters that contain all of the information required by the journal (as stated in the guideline for authors) can indicate that you have spent time carefully formatting the manuscript to fit the journal’s style. This creates a good first impression. Addressing the letter to a named editor at the journal also shows that you took the time to write your letter (and by extension, your manuscript) with care and considered the fit with the journal beyond just impact factor.
What makes an effective cover letter?
Cover letters should be short—preferably no more than 1 page—and they often use single line spacing. The content can be broadly divided into six sections:
Cover letters can be submitted as normal text files, such as Word, or input directly in a field in the journal’s online submission system.
- Addressee’s information and date of submission
- Opening salutation
- Purpose statement and administrative information
- Summary of main research findings and implications
- Statements or information required by the journal
- Closing salutation and your contact information
Let’s look at some tips for each section. And don’t forget to download the template, which shows these tips already in place.
1. Addressee’s information and date of submission
- Check the journal’s website for the name of the editor who handles submissions; this could be the Managing Editor or an editor assigned to your geographical region. If no handling editor is named, address your cover letter to the Editor-in-Chief. Some journals ask that you identify a specific editor for your specialty.
- Write the name of the addressee in the top left corner of the page.
- Write the date beneath. To minimize the number of line breaks used in your cover letter (and help keep it to one page of text), you can put the date to the right if you wish.
- Note that dates written as numerals only can be confusing: 02/03/2017 can be read “2 March 2017” in British and “3 February 2017” in American English. Using the format “3 February 2017” or “February 3, 2017” is clear.
2. Opening salutation
- Write the title and last name of the addressee (exclude the first name); for example, “Professor Brown” or “Dr. Baker” (British English: “Dr Baker”).
- If you can’t find a named editor on the journal website, then you can use the opening salutation “Dear Editor”.
- At the end of the opening salutation, you can use a comma or a colon; that is, “Dear Dr. Baker,” or “Dear Dr. Baker:” (British English uses the comma; American English uses either, but the colon is considered more formal).
3. Purpose statement and administrative information
- Clearly state the purpose of your letter (that you are submitting a manuscript) and then state your manuscript title, author names (or first author “Brown et al.”), and article type (e.g., original paper).
- Be sure to use the journal’s own terminology to refer to the article type; for example, some journals use the term “Regular Articles” for a full research paper, whereas others use “Original Submissions”, “Full Papers”, “Original Articles”, among others.
- See the downloadable Word template for an example sentence that presents this information clearly and concisely.
- If your submission consists of many files, consider summarizing them in one short sentence so that the journal editor is sure all of the files have been received; for example, “There are 8 files in all: 1 main manuscript file, 1 highlights file, 3 figure files, 1 table file, 1 supplementary data file, and 1 supplementary figures file”.
4. Summary of main research findings and implications
- In a new paragraph, summarize the purpose of your research (the research gap or problem it addresses), the main findings, and finally the implications of these findings. This is your main chance to highlight the value of your work to the journal editor, so keep this short and focused. (Journal editors may receive thousands of submissions annually, and many fulfill editing duties on top of their own research and teaching schedule, so you should strive to make their jobs easier by providing as concise a summary as possible.)
- Be sure to tailor your statements so that they're in line with the readership of the journal. For example, if you are submitting to a more general journal that has a diverse readership, underscore the possible impact your findings could have in multiple fields. Conversely, if you are submitting to a publication with narrow scope, you can write about your findings in highly focused terms.
- Avoid simply reproducing sentences verbatim from the abstract—which the journal editor will likely read next. Instead, if you take sentences from your abstract as a base to work from, then try to craft a much shorter summary that clearly fits the journal’s focus and that highlights the implications of your work for the journal’s readers. In fact, Nature guidelines state specifically to “avoid repeating information that is already present in the abstract and introduction.”
- When stating that you think your work is a good fit for the journal, be sure not to use exaggerated flattery. Avoid using words like “esteemed” and “prestigious” to describe the journal: “We believe that these findings will be of interest to the readers of your
- It’s helpful to the journal editor to state if your work directly relates to a paper published by another author in the same journal. Also, mention if your study closely relates to or extends your previously published work, so it is clear why your submitted manuscript is novel or important enough to publish.
Common phrases in this paragraph:
|Summarizing the purpose of your research|
|Presenting your main results|
|Highlighting the relevance of your findings|
5. Statements or information required by the journal
- In this new paragraph, provide any statements that the journal requires be included in your cover letter. Be sure to review the journal’s guidelines to know what information you should provide.
- Some journals or publishers have very specific requirements. For example, PLOS requires that authors describe any prior interactions with the journal in the cover letter, as well as suggest appropriate Academic Editors from the journal’s editorial board to handle the submission.
- Some journals require that sentences are provided verbatim in the cover letter. The guidelines will tell you to copy and paste the sentence provided in quotation marks into the cover letter. For example, Springer states that cover letters should contain two specific sentences: “We confirm that this manuscript has not been published elsewhere and is not under consideration by another journal” and “All authors have approved the manuscript and agree with its submission to [insert the name of the target journal].”
- Several statements pertaining to research and publication ethics are commonly required by journals across a broad range of fields. These are given in our downloadable Word template. When using the template, you can retain the statements in full, revise them slightly as appropriate to your circumstances, replace them with any similar wording required by the journal, or delete them if they do not fit your specific situation.
Common phrases in this paragraph:
|Previous contact with the journal|
|Conflict of interests and financial disclosures|
|Request to exclude reviewers|
6. Closing salutation and your contact information
- Briefly thank the journal editor for considering the manuscript and follow this with the full contact information of the corresponding author (name, academic degrees or professional qualifications; affiliation and postal address; telephone (and fax); email).
- Be sure to maintain a collegial tone to leave the journal editor with the best impression as he or she finishes reading your cover letter and moves on to evaluate your manuscript.
- Avoid statements that could be construed as presuming to give instructions to the editor. For example, “we look forward to your review of our manuscript” implicitly directs the editor to review your paper. Also, we look forward to hearing from you “at your earliest convenience/as soon as possible” implicitly directs the editor to communicate with you quickly; instead, simply use a neutral but polite phrase such as “we look forward to hearing from you” or “we look forward to hearing from you in due course”.
- A suitable closing salutation is “Sincerely,” or “Yours sincerely,”
Although the cover letter is not, strictly speaking, a part of your manuscript, it can affect how your submission is perceived by the journal editor. A cover letter that is tailored to the journal, introduces your work persuasively, and is free from spelling and grammatical errors can help prime the editor to view your submission positively before he or she even looks over your manuscript.
We hope our tips and Word template can help you create professional, complete cover letters in a time-effective way. Our specialist editors, translators, and writers are available to help create or revise the content to be error-free and, as part of our additional comprehensive Guidelines for Authors service, we can ensure the cover letter includes all of the statements required by the journal.
Lastly, just as a reminder for members of ThinkSCIENCE’s free annual rewards program, remember to claim your reward of free editing or translation of one cover letter alongside editing or translation of a full paper before the end of the March!