Blood Formatting Requirements: Complete Author Guide

ASH's pages disagree on whether original research abstracts are structured. The Manuscript Preparation page says abstracts for original research articles must contain the subheadings Background, Methods, Results, and Conclusions, while the Article Types page and the Blood Style Guide say the abstract must be a single paragraph with no subheadings. Check the current submission form. The abstract limit is 250 words for a Regular Article and 200 words for a Brief Report on the Article Types text and the Style Guide, although ASH's article-type table and Manuscript Preparation page list 300. We state the stricter limits.

If you use the subheadings, the Manuscript Preparation page lists:

• Background

• Methods

• Results

• Conclusions

One thing that catches authors off guard is the abstract cap. Journals like JAMA allow 350 words, and many hematology authors are used to writing longer abstracts for ASH meeting submissions. 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 (250 words) and "How I Treat" papers (200 words) use unstructured abstracts. 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 of no more than 120 characters including spaces (any abbreviation in the title must be defined in the abstract)

• 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 and tables, and number of references

Key Points go immediately before the Abstract: 1 to 2 statements, each 140 characters or fewer including spaces. ASH's Manuscript Preparation page says in one place that Key Points must be added at the revision stage and in another that they are required upon submission, so have them ready at submission. These are brief, tweet-length statements that summarize the main finding and its significance. They are published online, in First Edition, and in print immediately preceding the Abstract, are freely available on publication, and are not indexed by PubMed. Spend time on these. They're what most readers will see first.

Blood permits up to 7 figures in a Regular Article and 3 figures or tables combined in a Brief Report. This is more generous than many high-impact journals, which typically cap at 5 or 6. Authors are not charged any fee for figures published in color.

Figure requirements:

• Accepted formats for peer review: GIF, JPEG, PDF, TIFF, and EPS (PowerPoint is accepted but strongly discouraged)

• File size: the total PDF for peer review should not exceed 5 MB; high-resolution figures are required once a paper is accepted, and ASH's Digital artwork guidelines cover the print specifications

• Figure width: prepare figures 8.4 cm wide (1-column) or, if necessary, 12.7 cm wide (1½ column); the maximum width is 17.7 cm (2-column)

• Fonts and colors: ASH's production vendor may alter accepted figures to conform to Blood style, including standard colors and fonts

• Legends: begin each legend with a short, descriptive sentence in boldface, followed by a more detailed description in standard font

Table requirements:

• Every column except the leftmost stub column must have a column head

• Multipart tables (two or more separate sets of column heads) are not allowed and must be split into separate numbered tables

• Each table begins with "Table", its number, a period, and a brief, substantive title

• Abbreviations not expanded in the main text must be expanded in a footnote

• ASH recommends no more than 8 columns, so that a table fits on one US Letter page

Flow cytometry plots, karyotypes, and molecular pathway diagrams all need to meet ASH's print specifications once a paper is accepted. If you're exporting from FlowJo or GraphPad, check your export settings against ASH's Digital artwork guidelines before you finalize the figures.

Blood uses a numbered reference style that follows the AMA Manual of Style, 11th edition, as applied in the Blood Style Guide. References are numbered in the order of first citation 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 italicized and abbreviated according to the National Library of Medicine

• Include volume, issue number in parentheses, and inclusive page numbers

• Prepublished articles are cited with the DOI and the date of prepublication in place of the year, volume, and page numbers

• Online databases are cited with the author or institution, database name, URL, and access date

Worked example (Blood style, with the common wrong form shown for contrast):

Correct (Blood/AMA, period after the journal name, semicolon after the year): Smith AB, Jones CD, Williams EF. Targeting BCL-2 in chronic lymphocytic leukemia: a phase 2 trial. *Blood.* 2025;145(3):312-320.
Wrong (APA preset most reference managers default to): Smith, A. B., Jones, C. D., & Williams, E. F. (2025). Targeting BCL-2 in chronic lymphocytic leukemia: a phase 2 trial.

Blood, 145(3), 312-320.

The difference is what trips auto-exported bibliographies: Blood writes "Smith AB" with no commas or periods inside the name, abbreviates the journal per NLM, and uses a period (not a semicolon) between the journal name and the year; the APA form your reference manager exports by default uses "Smith, A. B." and is wrong for Blood.

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. ASH says the Editors review the supplemental material along with the manuscript, so don't treat it as an afterthought.

The data supplement can include:

• Additional figures and tables

• Extended methods

• Supplemental videos (QuickTime .mov, .avi, or Windows Media .wmv; ASH asks for videos under 5 MB, normally 30 to 45 seconds long)

• 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. All supplemental data other than videos must be submitted as a single Microsoft Word (.doc or .docx) file, with the methods, tables, figures, and legends in that order. Videos are uploaded separately and labeled "Video 1," "Video 2," etc.

ASH charges a $105 publication fee for each standard data supplement accompanying an accepted paper, plus another $105 for any supplement over 5 MB, and says supplemental data should not be used to circumvent the word count or figure limits. 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.

ASH's Manuscript Preparation page describes the manuscript as a text document with page numbers inserted into the header or footer. It does not mention LaTeX, a Blood LaTeX class file, required fonts, line spacing, or line numbering, so do not assume any of those rules apply.

Word submissions:

• Include page numbers in the header or footer of the text document

• Follow the section order on the Manuscript Preparation page: Title Page, Key Points, Abstract, Introduction, Methods, Results, Discussion, Acknowledgments, Authorship Contributions, Conflict of Interest Disclosures, References, Tables, Figure Legends, and Figures

• Supplemental data other than videos must be a single Microsoft Word (.doc or .docx) file

LaTeX submissions:

• ASH's Manuscript Preparation page does not mention LaTeX, so ask the Blood editorial office (editorial@hematology.org) before you plan a LaTeX submission

If you are comfortable with Word, use it, since it is the format ASH describes for supplemental data. If your paper is equation-heavy (pharmacokinetic modeling, for example), confirm the file format with the editorial office before you commit to a workflow.

Blood has several formatting requirements worth checking before you submit.

1. Visual Abstract requirement. ASH requires a visual abstract for original research articles, including Regular Articles and Brief Reports. It is welcome at initial submission but not required until the revision stage. This is a single pictorial summary of your main finding, which ASH also aims at social media dissemination. Build it on one of ASH's PowerPoint templates and submit it as a PowerPoint file, keeping the text boxes editable. Don't cram text into it. Use simple graphics and minimal labels.

2. Key Points are required for Regular Articles and Brief Reports. As noted above, you need 1 to 2 Key Points statements, each no more than 140 characters including spaces.

3. Blood Advances vs. Blood. When your paper is not accepted at Blood, you can opt in at submission to transfer it to another journal in the Blood Journals portfolio, such as Blood Advances, ASH's open-access companion journal. The editor notes and reviewer reports transfer with your files, and the receiving editors decide whether a different article type and format will be needed.

4. Data sharing statement required. Blood requires a Data Sharing Statement on the title page of every original research submission. For clinical trial reports, it should also state whether deidentified individual participant data will be shared, which data, and through what method.

Blood is the right formatting target when the manuscript is already clearly a hematology paper. The strongest fit is a study where disease biology, patient relevance, or hematopoietic mechanism is obvious from the title, abstract, Key Points, and first figure.

Who should avoid Blood? Authors whose paper mainly uses blood cells as an experimental system but does not answer a hematology question should not spend time polishing Blood-specific formatting until journal fit is resolved. That mismatch wastes more time than reference style, figure size, or title-page details.

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

The entire submission package should be ready before you start the online process. ASH says you have 30 days to complete a submission, and after 30 days all partial submissions are automatically deleted from the system.

For manuscripts targeting Blood, four patterns generate the most consistent desk-rejection outcomes.

In our pre-submission review work on Blood-bound manuscripts, we see a recurring failure pattern: authors treat formatting as a late production task, while Blood uses formatting details as evidence that the submission is operationally ready. That is an editorial triage pattern, not a cosmetic preference. We observe the same issue when the hematology story is strong but the Key Points, visual abstract, data statement, and disease-specific framing do not line up on first read.

Papers that pass early technical checks still face a demanding hematology-scope screen. Editors explicitly ask whether the manuscript belongs in Blood rather than a narrower hematology, immunology, thrombosis, or translational medicine journal. The formatting package should make that answer easy before peer review starts.

Key Points box missing or malformed. Blood requires Key Points for Regular Articles and Brief Reports: 1 to 2 statements summarizing the main finding and its significance, each 140 characters or fewer including spaces, placed immediately before the Abstract in both the submission form metadata and the text document. The assigned Editor reviews them, so Key Points that simply restate the abstract waste the slot.

Visual abstract absent or repurposed from a figure panel. Blood requires a visual abstract for original research articles by the revision stage: a single-image summary built on an ASH PowerPoint template, with minimal text and editable text boxes. ASH strongly recommends that it be a separate illustration, not a figure from your article.

Data availability statement insufficient for hematology research. Blood follows ASH data-sharing policies and requires a Data Sharing Statement on the title page of every original research submission. ASH requires high-throughput data (mRNA, miRNA, proteomic, and genomic DNA arrays) to be deposited in a public database such as GEO or ArrayExpress, with an accession number or link in the Methods. Its own example statements include "For original data, please contact [contact email address]."

Scope framing that lacks translational hematology context. Blood's editorial scope is hematological disease and hemostasis. Basic mechanistic studies on general cell biology pathways, even if conducted in blood cell lines, are rejected if they do not make a clear connection to a specific hematological disease or clinical question.

A Blood submission readiness check evaluates Key Points format, visual abstract compliance, data availability, and translational framing against these patterns.

The practical takeaway is simple: format Blood before you think the paper is finished. If the manuscript cannot produce a compliant Key Points section, a purpose-built visual abstract, a clear data availability statement, and a hematology-specific cover-letter claim, the formatting work is telling you that the submission strategy still needs revision.

For a manuscript-specific signal before you submit, run a Blood submission readiness check.

Or see example reports before you finalize.