Accession number (bioinformatics)

An accession number in bioinformatics is a unique identifier given to a DNA or protein sequence record to allow for tracking of different versions of that sequence record and the associated sequence over time in a single data repository. Because of its relative stability, accession numbers can be utilized as foreign keys for referring to a sequence object, but not necessarily to a unique sequence. All sequence information repositories implement the concept of "accession number" but might do so with subtle variations.

Accession numbers in specific data resources

UniProt (SwissProt) Knowledgebase

In UniProt documentation, the stated role of the accession number is "to provide a stable way of identifying entries from release to release." One entry (or record) might be associated with multiple accession numbers. Thus, in UniProt, there is no specific relationship between accession number and sequence; the primary relationship is between accession number and knowledgebase record, and a single knowledgebase record can refer to multiple sequences. In the flat version of the data, AC is the field delimiter for the accession number, the first being the "primary accession number" and all subsequent values being "seconary accession numbers". The proper key field for tracking a UniProt record is the primary accession number. The group of accession numbers associated with a knowledgebase record depends on the history of the record with respect to mergers and splits. New accession numbers arise in two main ways: new sequences (common) and knowledgebase record splits (rare).^[1]

GenBank

EMBL

DDBJ

Commonly encountered accession numbers

Notes and references

^ Amos Bairoch, Rolf Apweiler, Cathy H. Wu. "User Manual". UniProt Knowledgebase. Retrieved October 20, 2005.{{cite web}}: CS1 maint: multiple names: authors list (link)
This article incorporates public domain material from NCBI Handbook. National Center for Biotechnology Information.