# GenBank
**GenBank** is the National Institutes of Health genetic sequence database: an annotated, publicly available archive of nucleotide sequences, built and distributed by the [National Center for Biotechnology Information](https://www.edgepedia.org/national-center-for-biotechnology-information) (NCBI), a division of the National Library of Medicine on the NIH campus in [Bethesda, Maryland](https://www.edgepedia.org/bethesda-maryland)[1](https://ncbi.nlm.nih.gov/genbank/) • [2](https://pmc.ncbi.nlm.nih.gov/articles/PMC10767886/). It is one of three members of the International Nucleotide Sequence Database Collaboration (INSDC), exchanging data daily with the European Nucleotide Archive (ENA) in the United Kingdom and the [DNA Data Bank of Japan](https://www.edgepedia.org/dna-data-bank-of-japan) (DDBJ) in Mishima, Japan[1](https://ncbi.nlm.nih.gov/genbank/) • [3](https://www.ncbi.nlm.nih.gov/genbank/release/current/). GenBank serves as the archival, primary record of submitted sequence data; NCBI places no restrictions on its use or distribution[1](https://ncbi.nlm.nih.gov/genbank/).
| Key fact | Detail |
|---|---|
| Size (2025 update) | 34 trillion base pairs from over 4.7 billion nucleotide sequences covering 581,000 formally described species[4](https://academic.oup.com/nar/article/53/D1/D56/7903376) |
| Growth rate | Doubles in size approximately every 2 years[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC10767886/) |
| INSDC partners | Daily data exchange with ENA (Hinxton Hall, UK) and DDBJ (Mishima, Japan)[1](https://ncbi.nlm.nih.gov/genbank/) • [3](https://www.ncbi.nlm.nih.gov/genbank/release/current/) |
| Divisions | 21 divisions based on source taxonomy or sequencing strategy, including PAT, WGS, TSA, and TLS[4](https://academic.oup.com/nar/article/53/D1/D56/7903376) |
| Release cycle | Comprehensive release every two months via FTP, plus daily incremental updates; release 262 filled 5,374 flat files and 5.626 TB uncompressed[4](https://academic.oup.com/nar/article/53/D1/D56/7903376) |
| Relationship to RefSeq | GenBank is the archival primary record; RefSeq is a separate curated, non-redundant database synthesized from it and excluded from GenBank releases[5](https://academic.oup.com/nar/article-lookup/doi/10.1093/nar/gkl842) • [3](https://www.ncbi.nlm.nih.gov/genbank/release/current/) |
| Reuse terms | No restrictions on use or distribution, though submitters may claim patent, copyright, or other intellectual property rights in portions of their data[1](https://ncbi.nlm.nih.gov/genbank/) |
## History
GenBank originated at [Los Alamos National Laboratory](https://www.edgepedia.org/los-alamos-national-laboratory). Walter Goad, a Department of Energy scientist in LANL's Theoretical Biology and Biophysics Group who had spent the first 15 years of his 40-year DOE career developing thermonuclear weapons, spearheaded the effort to create a national repository of nucleic acid sequences[6](https://www.genomeweb.com/archive/genbank-turns-20). In September 1982, Elke Jordan and Carrico announced the database in a letter to *Science*, and in October 1982 the Los Alamos Sequence Library won a $2 million, five-year grant from the National Institute of General Medical Sciences and was christened "GenBank, the Nucleic Acid Sequence Data Bank"[6](https://www.genomeweb.com/archive/genbank-turns-20).
The database was small by modern standards. At the end of LANL's first five-year contract it held just over 15 million base pairs in 14,000 entries; after a second period working with Intelligenetics, it held 101 million bases and 78,000 sequences in 1992[6](https://www.genomeweb.com/archive/genbank-turns-20). In 2023 GenBank celebrated over 40 years of freely accessible sequence data as one of the earliest community scientific projects on the internet[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC10767886/).
## How data enters GenBank
The most important source of new data is direct submission from researchers using NCBI's submission tools[1](https://ncbi.nlm.nih.gov/genbank/). Submitted sequences undergo automated and manual processing before public release[1](https://ncbi.nlm.nih.gov/genbank/). Automated checks trim terminal NNNs and ambiguous sequence ends, remove low-quality sequences with more than 50% ambiguous nucleotides, identify vector and foreign contamination, and flag chimeric sequences, which may be removed[7](https://submit.ncbi.nlm.nih.gov/help/genbank/). Processing combines automated validations with manual review by NCBI staff; once issues are resolved, the submitter receives an email with GenBank accession numbers[7](https://submit.ncbi.nlm.nih.gov/help/genbank/).
Contamination screening has been strengthened in recent years. NCBI released the Foreign Contamination Screening (FCS-GX) tool, which detects contaminating sequences from organisms not arising from the intended biological source, and has fully incorporated it into standard processing of new prokaryotic and eukaryotic genome submissions[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC10767886/).
## Organization and format
GenBank data are partitioned into 21 divisions based on either the source taxonomy or the sequencing strategy; these include PAT (sequences from patent offices), WGS (whole genome shotgun), TSA (transcriptome shotgun assembly), and TLS[4](https://academic.oup.com/nar/article/53/D1/D56/7903376). Through agreements with the U.S. Patent and Trademark Office, and through the partner databases of the international collaboration with other patent offices, sequences from patents are added to the collection.[3](https://www.ncbi.nlm.nih.gov/genbank/release/current/)
A comprehensive GenBank release occurs every two months and is available from the FTP site, with daily incremental updates in between[1](https://ncbi.nlm.nih.gov/genbank/) • [4](https://academic.oup.com/nar/article/53/D1/D56/7903376). The database is distributed in GenBank Flatfile and Abstract Syntax Notation 1 ([ASN.1](https://www.edgepedia.org/asn-1)) formats[3](https://www.ncbi.nlm.nih.gov/genbank/release/current/). For release 262 (15 August 2024), the release comprised 5,374 flat files requiring 5.626 TB of uncompressed disk storage[4](https://academic.oup.com/nar/article/53/D1/D56/7903376).
## GenBank, RefSeq, and the INSDC
GenBank records are submitter-authored archival records. RefSeq, by contrast, is a curated non-redundant collection of sequences representing genomes, transcripts, and proteins; RefSeq records are synthesized from GenBank data and may include feature annotation, names, or other data not present in the GenBank records from which they were derived[5](https://academic.oup.com/nar/article-lookup/doi/10.1093/nar/gkl842). RefSeq records are not part of GenBank, although both can be retrieved through the same NCBI interfaces such as Entrez Nucleotide and Entrez Protein[5](https://academic.oup.com/nar/article-lookup/doi/10.1093/nar/gkl842). RefSeq curation status terms, annotated as a COMMENT feature, include model, predicted, provisional, inferred, validated, and reviewed[5](https://academic.oup.com/nar/article-lookup/doi/10.1093/nar/gkl842).
GenBank is the major source of primary data NCBI uses to produce RefSeq and NCBI Gene; conceptual translations of GenBank coding sequences form the largest component, 53%, of the Entrez Protein collection[4](https://academic.oup.com/nar/article/53/D1/D56/7903376). GenBank releases exclude Third-Party Annotation (TPA) records and RefSeq records; GenBank is the archival resource those efforts draw on[3](https://www.ncbi.nlm.nih.gov/genbank/release/current/).
## By the numbers
Growth has been exponential. The 2024 update reported 25 trillion base pairs from over 3.7 billion sequences for 557,000 formally described species; one year later the 2025 update reported 34 trillion base pairs from over 4.7 billion sequences for 581,000 species[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC10767886/) • [4](https://academic.oup.com/nar/article/53/D1/D56/7903376). GenBank doubles in size approximately every 2 years[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC10767886/).
The current release notes give a more granular accounting: 267,383,895 traditional sequences totaling 8,236,878,868,450 bases, plus 6,409,108,932 set-based (WGS/TSA/TLS) sequences totaling 51,833,865,624,995 bases[3](https://www.ncbi.nlm.nih.gov/genbank/release/current/). These release-note totals, roughly 60 trillion bases, exceed the 34 trillion figure of the 2025 NAR update; the two figures are reported here as published, without reconciliation, and readers should note which counting a given statistic uses.
## Data quality and limitations
Errors in GenBank records arise at several stages of the research process: sample misidentification, laboratory and cross-sample contamination, sequencing and sequence-editing mistakes, and labeling or data-entry errors during upload[8](https://pmc.ncbi.nlm.nih.gov/articles/PMC12186718/). A 2019 analysis of Metazoan mitochondrial data concluded that GenBank is generally reliable, with low mislabeling rates at higher taxonomic levels, but that incorrect assignments reach about 3.5% at the genus level[8](https://pmc.ncbi.nlm.nih.gov/articles/PMC12186718/).
Correction policy is conservative: only the original submitter, or GenBank staff under written agreement from the submitter, can modify or correct an entry once submitted[8](https://pmc.ncbi.nlm.nih.gov/articles/PMC12186718/). GenBank began accepting direct sequence submissions in 1993[8](https://pmc.ncbi.nlm.nih.gov/articles/PMC12186718/). Automated screening, including the FCS-GX contamination check now standard for genome submissions, is the main mitigation NCBI applies on its side[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC10767886/).
## Recent developments
Several operational changes have reshaped submission and search since 2023:
- **Tool consolidation.** tbl2asn was retired and replaced by table2asn; by summer 2024 NCBI no longer accepted submissions prepared with tbl2asn[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC10767886/). Starting in spring 2026, all GenBank submissions are being consolidated into the Submission Portal, and BankIt will be phased out[9](https://ncbiinsights.ncbi.nlm.nih.gov/2026/01/27/bankit-submitters-upcoming-changes-to-how-you-submit-to-genbank/). The Submission Portal already supports uploading feature tables for mRNA sequences as part of this transition[4](https://academic.oup.com/nar/article/53/D1/D56/7903376).
- **Minimum standards.** NCBI now requires submitted data to meet the relevant INSDC minimal requirements before GenBank or SRA will process it, assign an accession number, and publish it; submissions that fail are not accepted[10](https://ncbiinsights.ncbi.nlm.nih.gov/2026/03/18/ncbi-insdc-minimal-specifications/).
- **Human data policy.** Since June 16, 2026, GenBank no longer accepts personal sequence data, including personal human chromosome, genome, or mitochondrial DNA data, from private individuals[11](https://www.nlm.nih.gov/pubs/techbull/mj26/mj26_genbank.html).
- **Search and release speed.** In 2024 NCBI released core_nt, a new default BLAST database that increases search efficiency and reduces redundancy in search results[4](https://academic.oup.com/nar/article/53/D1/D56/7903376). It also expedited release of influenza sequences, so submitters obtain accession numbers and public access within hours rather than days, with FLAN-based automated annotation and quality checks[4](https://academic.oup.com/nar/article/53/D1/D56/7903376).
- **Metadata.** Recent updates include policies for spatio-temporal metadata and new Submission Portal processes, including eukaryotic nuclear mRNA workflows[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC10767886/).
## References
1. [GenBank Overview, NCBI](https://ncbi.nlm.nih.gov/genbank/)
2. [GenBank 2024 Update, Nucleic Acids Research](https://pmc.ncbi.nlm.nih.gov/articles/PMC10767886/)
3. [Current GenBank Release Notes, NCBI](https://www.ncbi.nlm.nih.gov/genbank/release/current/)
4. [GenBank 2025 update, Nucleic Acids Research](https://academic.oup.com/nar/article/53/D1/D56/7903376)
5. [NCBI reference sequences (RefSeq): a curated non-redundant sequence database, Nucleic Acids Research](https://academic.oup.com/nar/article-lookup/doi/10.1093/nar/gkl842)
6. [GenBank Turns 20, GenomeWeb](https://www.genomeweb.com/archive/genbank-turns-20)
7. [Submission Portal GenBank Help, NCBI](https://submit.ncbi.nlm.nih.gov/help/genbank/)
8. [In Vouchers We (Hope to) Trust: Unveiling Hidden Errors in GenBank's Tetrapod Taxonomic Foundations](https://pmc.ncbi.nlm.nih.gov/articles/PMC12186718/)
9. [BankIt Submitters: Upcoming Changes to How You Submit to GenBank, NCBI Insights](https://ncbiinsights.ncbi.nlm.nih.gov/2026/01/27/bankit-submitters-upcoming-changes-to-how-you-submit-to-genbank/)
10. [NCBI Adopts INSDC Minimal Specifications for GenBank and SRA, NCBI Insights](https://ncbiinsights.ncbi.nlm.nih.gov/2026/03/18/ncbi-insdc-minimal-specifications/)
11. [GenBank: Changes to Human Sequence Submissions, NLM Technical Bulletin](https://www.nlm.nih.gov/pubs/techbull/mj26/mj26_genbank.html)
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*Topic: Encyclopedia › Technology and the built world › Computing and digital systems › Artificial intelligence and data › Databases and data systems › Subject-specific databases › Biological and bioinformatics databases › Nucleotide and genome databases*
*Initially written Sep 17, 2026 · Reviewed: Oct 15, 2026 · Edited: Oct 15, 2026 · Last review: Oct 15, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license