Supplementary information

Table of contents:

• 1. General information
• 2. Content
• 3. Format and file sizes
• 4. Submitting Supplementary Information
• 5. Supplementary Information checklist
• 6. Microarrays and other databases

1. General information

• SI is peer-reviewed material directly relevant to the conclusion of a paper that cannot be included in the printed version for reasons of space or medium (for example, movie clips or sound files).
  
  
• Nature strongly encourages authors to include a simple schematic as Figure 1 of their SI that summarises the main finding of the paper, where appropriate (for example, to assist understanding of complex detail in cell, structural and molecular biology disciplines).
  
  
• SI is not subedited so authors should ensure that it is clearly and succinctly presented, and that the style of terms conforms with the rest of the paper. During SI processing for online publication, standard house formatting will be applied but the contents will remain unchanged.
  
  
• SI is posted on the freely available part of our website at the time of publication and cannot be hosted solely on the authors' own websites for peer-review or publication purposes. Nor can it be altered by the author after the paper has been accepted for publication.
  
  
• We do not take responsibility for the maintenance of any links or e-mail addresses provided in SI.

2. Content

We recommend that, in all sections of the journal except Brief Communications Arising (for which Supplementary Information is not permitted), Supplementary Information in the following "flat" (text or figure) categories is combined into a single PDF, laid out as you wish readers to download it. Each legend should be written directly beneath its figure.

1. Supplementary Figure(s) and Legend(s)
2. Supplementary Methods
3. Supplementary Table(s)
4. Supplementary Discussion
5. Supplementary Equation(s)
6. Supplementary Notes (including notes clarifying statistical analyses, acknowledgements, grant or other numbers)
7. Supplementary Movie Legend(s)
8. Supplementary Audio Legend(s)

Although files will be combined into a single PDF when possible, data, audio and movie files will be posted separately. When combining your 'flat' SI into a PDF for online publication, you should avoid inserting header or footer information (including pagination) into your documents, and you should leave sufficient space (approximately 2.5 cm at the top and bottom of the document) for standard headers and footers to be inserted during in-house SI processing.

See section 3 for advice on file sizes. Briefly, PDFs should be as small as possible but can be up to 5 MB if necessary.

Some types of SI (listed below) are either best presented in editable format or cannot be presented as PDF for technical reasons. Please supply these types of SI in one of our allowable formats. They will be published with the PDF of the rest of your SI, downloadable as separate files.

 9.  Supplementary Data
10. Supplementary Movie(s)
11. Supplementary Audio(s)

Tips and hints for presentation of SI.

• SI sections should be classified as one of the eleven categories above (contact the handling editor if you wish to submit material that is not covered by one of these categories).
• A text summary for each file (no more than 50 words) that describes the contents of the file. The description should indicate how many figures and what type of text are contained within the file, and provide a general description of what the figures collectively show. Descriptions of separate files (movies, audio files) should also be provided. These summaries will be displayed in the SI Table of Contents as a guide for readers.
• Please note that we do not encourage deposition of references within SI as they will not be live links and will not contribute towards citation measures for the papers concerned. Authors who nevertheless wish to post reference lists should use the "Supplementary Notes" category and continue the numbering from the last reference listed in the print version, rather than repeating the numbering in the print version.
• Supplementary tables and figures must have a separate numbering system from that used for tables and figures that apppear in the print version of the paper (the first figure displayed in SI should be labelled "Supplementary Figure 1", the first table "Supplementary Table 1", and so on).
• With your SI, please include an additional "SI Guide" text file named SIGuide.doc. This should contain:
• 1. A title for each file (for example, for a merged PDF: Supplementary Figures and Legends 1-4; Supplementary Methods; Supplementary Notes. For example, for SI supplied as separate files: Supplementary Figure 1).
  2. A text summary for each file (no more than 50 words) that describes the contents of the file. Descriptions of individual figures or tables should be provided if these items are submitted as separate files. For SI submitted together in one PDF, the description should indicate how many figures and what type of text are contained within the file, and provide a general description of what the figures collectively show. These summaries will be displayed in the SI Table of Contents as a guide for readers.
  3. The file type and file size in parentheses.

     For example:
     Supplementary Movie 1

     This movie shows the dorsal view of a wild-type embryo labelled with X to reveal cell movements. The time lapse covers a period of about X min, during which time a new X is established. By following cells during the course of the movie, it is evident that there are rearrangements of cells during X formation (QuickTime; 3 MB).

• Ensure that each piece of SI (or, if appropriate, "Supplementary Information" in general) is referred to at least once in the print version of the paper at an appropriate point in the text, and after references using the following sentence: "Supplementary Information is linked to the online version of the paper at www.nature.com/nature." If you have provided a schematic or other device to assist the non-specialist reader as SI, it is especially helpful to refer to this explicitly in the first non-bold paragraph or other appropriate place in the print version.

3. Format and file sizes

• Ensure that file sizes are as small as possible so that users can download them quickly.
• Images should be a maximum size of 640 x 480 pixels (9 x 6.8 inches at 72 pixels per inch).
• We prefer to accept no more than ten files, with a total size not normally exceeding 3 MB. Sound/movie files may be up to 10 MB per file; colour PDFs/PowerPoint may be up to 5 MB per file; all other general file types may be up to 2 MB per file but most files will be much smaller.
• We accept files in any of the following formats:
  • Adobe Acrobat (.pdf) (preferred)
  • MS Word document (.doc)
  • Plain ASCII text (.txt)
  • Rich Text Format (.rtf)
  • WordPerfect document (.wpd)
  • PostScript (.ps)
  • Encapsulated postcript (.eps)
  • HTML document (.htm)
  • MS Excel spreadsheet (.xls)
  • GIF image (.gif)
  • JPEG image (.jpg)
  • TIFF image (.tif)
  • MS PowerPoint slide (.ppt)
  • QuickTime movie (.mov) (preferred; note that for technical reasons, we cannot accept wmv (Windows Media Player) files)
  • Flash movie (.swf)
  • Audio file (.wav)
  • MPEG/MPG animation (.mpg)
  • Systems Biology Markup Language (.sbml, .xml, .owl)

If your file sizes exceed these limits or if you cannot submit in these formats, please seek advice from the editor handling your manuscript.

Should you require assistance with file formats or uploading of your Supplementary Information, you can contact us at supplementary@nature.com.

4. Submitting Supplementary Information

• For intitial submissions, SI can be submitted online with the rest of the paper via our online submission sevice.
• When a paper with SI is accepted, SI in its final form should be uploaded to our server via our online submission service. In addition to the SI files, please also upload the SIGuide.doc as specified above (this should provide a list of file names with a brief description of what each file contains and the file format and size)
• If you are unable to upload production-quality files to our server, you should contact Nature's London office (production_submit@nature.com) for details of how files may be sent on disk, although you should be aware that online submission is the preferred route and submission by other means may delay acceptance and/or publication of your paper.

5. Supplementary Information checklist

Please check the following when submitting SI:

1. Each piece of SI designated to one of eleven categories with a separate numbering system from that used for figures and tables in the print version of the paper.
2. Formats are among those accepted by Nature.
3. Total size of all files does not exceed 3 MB (unless sound/movie file).
4. SIGuide.doc text file submitted containing titles of each SI file, descriptive summaries, file format types and file sizes.

6. Microarrays and other databases

Please see the MGED open letter specifying microarray standards.

• Authors submitting manuscripts containing microarray data must supply the data as SI on a CD at the time of submission. Five copies of the CD are required.
• The data must be MIAME-compliant, with all variables completed.
• We also require submission of microarray data to the GEO or ArrayExpress databases, with accession numbers at or before acceptance for publication.
• See Nature editorial of 26 September 2002 for further details and explanation.