bioRxiv’s microbiology collection holds more than 41,000 preprints as of July 2026, making it the platform’s third-largest subject area behind neuroscience (over 90,000) and bioinformatics (nearly 43,000). Together, these three fields account for close to two-fifths of every preprint ever posted to bioRxiv since its 2013 launch — a concentration that says as much about where biology’s fastest-moving fields are as it does about the platform itself.
bioRxiv is a free, non-profit preprint repository for the biological sciences, now operated by openRxiv, on which authors post manuscripts before or independent of journal peer review, sorted into 27 subject-specific collections spanning everything from paleontology to synthetic biology.
- What is bioRxiv, and how are preprints organised by subject?
- How does bioRxiv microbiology compare to neuroscience and other subjects by volume?
- Why does subject-level concentration matter for research administrators?
- Common questions about bioRxiv preprints
- Implications and outlook for scholarly communication
What is bioRxiv, and how are preprints organised by subject?
bioRxiv was co-founded by John Inglis and Richard Sever in November 2013 as an open-access preprint repository hosted by Cold Spring Harbor Laboratory. In March 2025, bioRxiv and its clinical-sciences counterpart medRxiv transferred to openRxiv, a newly formed non-profit created specifically to steward both platforms, as reported by Science.
Every submission is placed into one of 27 subject collections at the point of posting. There is no fee to submit to bioRxiv, and authors self-select the collection that best matches their manuscript. This subject taxonomy is what makes volume comparisons across fields possible — and what this analysis draws on directly.
One structural exception worth noting: the Epidemiology collection is now closed to new submissions following the completion of bioRxiv’s clinical-research pilot project, meaning its growth curve has effectively flattened while other collections continue to expand.
How does bioRxiv microbiology compare to neuroscience and other subjects by volume?
Based on a live count of bioRxiv’s own subject-collection pages taken on 3 July 2026, neuroscience is the platform’s largest single collection at 90,290 preprints — a 19.4% share of the roughly 465,700 preprints posted across all 27 collections to date. Bioinformatics follows at 42,825 (9.2%), with microbiology close behind at 41,133 (8.8%).
Cell biology, evolutionary biology, genomics and biophysics round out the next tier, each holding between roughly 21,000 and 26,000 preprints. At the other end of the scale, paleontology (678) and clinical trials (138) remain niche collections by comparison, while epidemiology’s 2,067 total is now largely fixed given its closure to new submissions.
Full ranking of bioRxiv’s largest subject collections
| Rank | Subject collection | Cumulative preprints | Share of total |
|---|---|---|---|
| 1 | Neuroscience | 90,290 | 19.4% |
| 2 | Bioinformatics | 42,825 | 9.2% |
| 3 | Microbiology | 41,133 | 8.8% |
| 4 | Cell Biology | 25,753 | 5.5% |
| 5 | Evolutionary Biology | 24,737 | 5.3% |
| 6 | Genomics | 22,868 | 4.9% |
| 7 | Biophysics | 21,837 | 4.7% |
| 8 | Ecology | 20,284 | 4.4% |
| 9 | Cancer Biology | 18,775 | 4.0% |
| 10 | Biochemistry | 18,098 | 3.9% |
Source: CASRAI analysis of live bioRxiv subject-collection article counts, recorded 3 July 2026. These are cumulative totals since bioRxiv’s 2013 launch, not annual submission rates, so they reflect sustained field-level adoption of preprinting rather than a single year’s activity.
Microbiology’s position just behind bioinformatics is notable given how differently the two fields work: bioinformatics preprints are often fast, computational and low-cost to produce, while microbiology preprints typically follow wet-lab experimental cycles. That microbiology has nonetheless built a corpus within a few thousand papers of bioinformatics points to strong, sustained preprinting culture within microbiology specifically — likely reinforced by the field’s pandemic-era experience with rapid-dissemination norms.
Why does subject-level concentration matter for research administrators?
For institutional leaders and research-administration teams, subject-level preprint concentration is a proxy for where scholarly communication norms are shifting fastest. A field with tens of thousands of preprints has, in effect, normalised pre-peer-review dissemination as a routine step in its publication workflow — with direct implications for how institutions track outputs, credit early dissemination in tenure and promotion review, and advise researchers on preprint policy.
- Grant and promotion committees increasingly need clear policy on whether preprints count as citable outputs, particularly in high-volume fields like neuroscience and microbiology.
- Research offices supporting microbiology, bioinformatics or genomics groups should expect preprint-first workflows to already be the norm, not the exception, among active researchers.
- Fields with low preprint volume (pathology, zoology, clinical trials) may need different guidance, since preprinting culture there remains comparatively immature.
This is also a live concern for research administrators and institutional leaders tracking how open-research norms diffuse unevenly across disciplines — subject-level data of this kind gives institutions a concrete basis for that assessment, rather than relying on anecdote.
Common questions about bioRxiv preprints
Is bioRxiv a preprint server?
Yes. bioRxiv is a dedicated preprint server for the biological sciences, distributing manuscripts before or alongside formal peer review. It is operated by openRxiv, a non-profit created in 2025 specifically to run bioRxiv and medRxiv, and hosts subject collections spanning microbiology, neuroscience, genomics and 24 other biology-related fields.
Can anyone submit to bioRxiv?
Authors can deposit a manuscript in draft or final form provided it concerns a relevant scientific field, is unpublished at the time of submission, and all co-authors have consented. Authors must first register on the platform. bioRxiv screens submissions for basic scope and ethical compliance before posting, but does not conduct peer review.
How much does it cost to publish in bioRxiv?
There is no fee to submit a preprint to bioRxiv. This free-to-post model is a key driver of its growth across every subject collection, including the microbiology and neuroscience volumes analysed above, since it removes the cost barrier that applies to many open-access journal publication routes.
Does bioRxiv count as published?
A bioRxiv preprint is not equivalent to a peer-reviewed publication. It establishes a timestamped, citable public record of the work, and many journals allow later submission of the same manuscript, but it has not undergone formal peer review at the point of posting. Institutions and funders vary in how they weight preprints in assessment.
Implications and outlook for scholarly communication
The concentration of preprint volume in neuroscience, bioinformatics and microbiology is likely to persist rather than reverse. These fields combine large, active researcher populations with production cycles well suited to rapid dissemination, and none shows structural barriers comparable to epidemiology’s now-closed pilot pathway.
For research-administration teams, the practical takeaway is to treat preprint-volume data by subject as a planning input: policy on preprint citation, researcher guidance, and repository integration should be calibrated to each discipline’s actual adoption level rather than applied uniformly across an institution’s full research portfolio.