Blood Formatting Requirements: Complete Author Guide

Blood publishes several distinct article types, and each one has specific length requirements. Exceeding these limits will trigger an administrative return before your paper reaches an editor.

Word counts exclude the abstract, references, figure legends, and table content. The "How I Treat" series is an invited format, but unsolicited proposals are occasionally considered if you contact the editors first.

Blood requires structured abstracts for Original Articles and Short Reports. The abstract can't exceed 200 words, which is tighter than most comparable journals. You need to be concise.

The required headings are:

• Background (or can be omitted if space is tight)
• Methods
• Results
• Conclusions

One thing that catches authors off guard is the 200-word cap. Journals like JAMA allow 350 words, and many hematology authors are used to writing longer abstracts for ASH meeting submissions (which allow 250 words). For Blood, you'll need to cut hard. Focus on the primary finding and its clinical or biological significance. Don't list every secondary endpoint.

Review Articles and "How I Treat" papers use unstructured abstracts, also capped at 200 words. These should summarize the scope and main conclusions without using section headings.

Blood requires a separate title page as the first page of your manuscript. It must include:

• Full title (no abbreviations unless universally understood, like DNA or HIV)
• Short running title of 50 characters or fewer
• All author names with first name, middle initial, and last name
• Institutional affiliations numbered and listed below the author line
• Corresponding author's name, mailing address, phone, fax, and email
• Word count for body text and abstract listed separately
• Number of figures, tables, and supplemental files
• Key Points: 2 sentences, 140 characters max total

The Key Points requirement is specific to Blood and relatively new. These are brief, tweet-length statements that summarize the main finding and its significance. They appear in the online table of contents and social media promotion. Spend time on these. They're what most readers will see first.

Blood permits up to 8 figures in an Original Article. This is more generous than many high-impact journals, which typically cap at 5 or 6. All figures are published in full color at no charge, both in print and online.

Figure requirements:

• Minimum resolution: 300 DPI for photographs and halftones, 1,000 DPI for line art
• Accepted formats: TIFF, EPS, or high-resolution PDF
• Maximum figure width: 3.25 inches (single column) or 6.75 inches (double column)
• Font in figures: Arial, minimum 8-point after sizing
• Multipanel figures (A, B, C) count as one figure
• Each figure must be uploaded as a separate file

Table requirements:

• Tables must be created in Word using the table function, not pasted as images
• Every column needs a header row
• Use horizontal rules only (top, bottom, and below headers)
• No vertical rules or shading
• Abbreviations must be defined in table footnotes
• P values should be reported to 2-3 decimal places

Blood's figure resolution requirements for line art (1,000 DPI) are stricter than most journals. Flow cytometry plots, karyotypes, and molecular pathway diagrams all need to meet this threshold. If you're exporting from FlowJo or GraphPad, check your export settings before submission.

Blood uses a numbered reference style based on Vancouver/NLM conventions. References are numbered consecutively in the order they first appear in the text and cited using superscript numbers.

Key formatting rules:

• Superscript numbers in text, placed after punctuation
• List all authors up to 6; if more than 6, list the first 3 followed by "et al"
• Journal titles abbreviated per NLM standards (Index Medicus)
• Include volume, first page, and last page numbers
• DOIs are encouraged but not required
• Don't include database accession numbers in the reference list

Example reference:

Smith AB, Jones CD, Williams EF. Targeting BCL-2 in chronic lymphocytic leukemia: a phase 2 trial. Blood. 2025;145(3):312-320.

For citing ahead-of-print articles:

Include the DOI and note "published online ahead of print" with the date.

One formatting detail that trips people up: Blood uses a period (not a semicolon) between the journal name and the year. This is different from some implementations of Vancouver style. If you're using a reference manager, make sure your Blood output style is current. Zotero and Mendeley both have Blood-specific styles, but they aren't always updated to reflect the latest requirements from the ASH author guidelines.

Blood calls its supplementary material a "data supplement." It's hosted online and linked from the published article. Reviewers can access it during peer review, so don't treat it as an afterthought.

The data supplement can include:

• Additional figures and tables
• Extended methods
• Supplemental videos (MP4 format preferred, 10 MB max per video)
• Raw data files
• Additional statistical analyses

Each supplemental figure should be labeled as "Supplemental Figure 1," "Supplemental Figure 2," etc. Tables follow the same convention. The data supplement is submitted as a single PDF file that combines all supplemental figures, tables, and text. Videos are uploaded separately.

Blood doesn't impose a strict size limit on the data supplement, but keep it focused. A 100-page supplement suggests you're trying to publish two papers in one. Reviewers notice and it affects their assessment of your manuscript's clarity.

Blood accepts manuscripts in both Microsoft Word and LaTeX format. However, Word is the more commonly used format, and Blood's production workflow is optimized for it.

Word submissions:

• Use standard fonts (Times New Roman or Arial, 12-point)
• Double-space the entire manuscript
• Number all pages consecutively
• Use continuous line numbering throughout

LaTeX submissions:

• Blood provides a class file (blood.cls) available through the submission system
• Use the standard Blood template if available
• Convert all custom macros to standard LaTeX commands
• Submit the compiled PDF alongside source files
• Include all .bib, .bst, and custom style files

If you're comfortable with Word, use it. Blood's copyediting team works in Word, and LaTeX submissions get converted during production. That conversion sometimes introduces formatting errors, especially in complex equations or specialized notation. If your paper is equation-heavy (pharmacokinetic modeling, for example), LaTeX may still be the better choice since the equations will render more reliably, but expect some back-and-forth during proofs.

Blood has several formatting requirements that differ from other hematology journals. Missing these is one of the most common reasons for administrative returns.

1. Visual Abstract requirement. Blood strongly encourages (and for some article types, requires) a visual abstract. This is a single-panel graphical summary of your main finding, designed for social media sharing. The visual abstract must be 1,280 x 720 pixels, in landscape orientation, and submitted as a separate file. Don't cram text into it. Use simple graphics and minimal labels.

2. Key Points are mandatory. As noted above, you need exactly 2 Key Points statements, and the combined character count can't exceed 140 characters. These aren't optional, and the system won't let you submit without them.

3. Blood Advances vs. Blood. When your paper is rejected from Blood, you can opt in to automatic transfer to Blood Advances, the ASH's open-access companion journal. The formatting requirements are nearly identical, but Blood Advances has different word limits for some article types. If you select the transfer option at submission, your manuscript moves over without reformatting.

4. Data sharing statement required. Blood requires a data sharing statement indicating whether individual participant data will be available, what data will be shared, and through what mechanism. This goes on the title page.

5. ORCID requirement. The corresponding author must have an ORCID iD linked to their ScholarOne account. Co-authors are encouraged but not required to provide ORCIDs.

Blood uses the ScholarOne Manuscripts system for submissions. Here's the file preparation checklist:

1. Main manuscript (Word or LaTeX): title page, abstract with Key Points, body text, references
2. Figures: each uploaded separately as TIFF, EPS, or PDF (300+ DPI, 1,000+ DPI for line art)
3. Tables: embedded in the manuscript file at the end, one table per page
4. Data supplement: single combined PDF of all supplementary material
5. Visual abstract: 1,280 x 720 px, separate file
6. Cover letter: addressing the editor, stating novelty and fit for Blood
7. Reporting checklist: CONSORT, STROBE, etc. as applicable
8. Conflict of interest forms: for all authors

The entire submission package should be ready before you start the online process. ScholarOne times out if you take too long between steps, and you'll have to restart.

Based on the most frequent administrative returns at Blood, here are the mistakes to watch for:

• Exceeding the 200-word abstract limit (this is enforced automatically)
• Missing Key Points on the title page
• Submitting figures below the minimum resolution
• Forgetting the data sharing statement
• Using non-standard abstract headings
• Exceeding the running title character limit (50 characters)
• Not including line numbers in the manuscript

For quick answers to the most common Blood formatting questions, see the FAQ section at the top of this page.