NCBI logo gif RefSeq banner gif
PubMed All Databases BLAST OMIM Books Taxonomy Structure

  NCBI Reference Sequences

The Reference Sequence (RefSeq) collection aims to provide a comprehensive, integrated, non-redundant, well-annotated set of sequences, including genomic DNA, transcripts, and proteins. RefSeq is a foundation for medical, functional, and diversity studies; they provide a stable reference for genome annotation, gene identification and characterization, mutation and polymorphism analysis (especially RefSeqGene records), expression studies, and comparative analyses. [more...]

blue marker gifScope back to top

NCBI provides RefSeqs for taxonomically diverse organisms including eukaryotes, bacteria, and viruses.

blue marker gifAnnouncements back to top

October 26, 2012: The Consensus CDS (CCDS) database released an update for human following genome reannotation by NCBI and Ensembl (Assembly GRCh37.p9, assembly accession GCF_000001635.21, NCBI homo sapiens annotatio release 103, Ensembl annotation release 68). This update adds 1138 new CCDS IDs, reinstates 2 previously withdrawn CCDS ID, and adds 93 Genes into the human CCDS set. This release includes a total of 27,511 CCDS IDs that correspond to 18,535 GeneIDs.

September 21, 2012: RefSeq Release 55 available for FTP

This release includes:

Available at:

To receive announcements of future RefSeq releases and incremental large updates please subscribe to NCBI's refseq-announce mail list: refseq-announce


Announcing the Consensus Coding Sequence (CCDS) database. More information is available at:

BLAST databases: Formatted genomic, mRNA, and protein RefSeq BLAST databases are available for FTP.

announcing HIV-1 protein interaction data, more information at

blue marker gifData Access and Availability back to top

RefSeq is accessible via BLAST, Entrez, and the NCBI FTP site. Information is also available in Entrez Genomes and Entrez Gene, and for some genomes additional information is available in the Map Viewer. Special properties have been defined to facilitate Entrez-based retrieval. Also see: Entrez Query Hints

blue marker gifDistinguishing Features back to top

The main features of the RefSeq collection include:
blank spacer gif  non-redundancy
blank spacer gif  explicitly linked nucleotide and protein sequences
blank spacer gif  updates to reflect current knowledge of sequence data and biology
blank spacer gif  data validation and format consistency
blank spacer gif  distinct accession series (all accessions include an underscore '_' character)
blank spacer gif  ongoing curation by NCBI staff and collaborators, with reviewed records indicated

blue marker gifReferences back to top

Please refer to the Publications page for a full list of articles describing or using the RefSeq dataset. When using the RefSeq database, please cite one of the following:

The NCBI handbook [Internet]. Bethesda (MD): National Library of Medicine (US), National Center for Biotechnology Information; 2002 Oct. Chapter 18, The Reference Sequence (RefSeq) Project. Available from

NCBI Reference Sequences (RefSeq): current status, new features and genome annotation policy.
Pruitt KD, Tatusova T, Brown GR, Maglott DR.
Nucleic Acids Res. 2012 Jan;40(Database issue):D130-5.
[Full Text in PubMed Central]

 Site contents spacer gif  
NCBI Handbook
Overview  |  FAQ Frequently Asked Questions
Accessions  |  Status  |  Queries  |  Publications
RefSeq Release
Catalog  |  Notes
BLAST databases
Release Statistics
NCBI Help Desk
Submit Updates
Submit GeneRIF
Subscribe to email list or RSS
RefSeq  |  Gene News (RSS)
Map Viewer  |  NCBI
Related links
Genomic Biology Home
Gene  |  Genome Project
Entrez Genomes Home
Map Viewer  |  UniGene
Microbial Providers
Viral Genome Advisors

Last updated October 26, 2012
Questions or Comments?
Write to the Help Desk

Disclaimer     Privacy statement