Genes in listings etc. often have a number of the type NC_000012.12 associated with them. How should this be interpreted?

  • $\begingroup$ I have edited your question so the title is more useful to others, in view of your original misunderstanding and the correct answer supplied by @JITZ. $\endgroup$
    – David
    Apr 6, 2017 at 12:09

1 Answer 1


This particular ID represent RefSeq accession number. NC_ stands for a genomic molecule representing complete genomic molecule, usually reference assembly. Every sequence has a stable accession number, a version number, and an integer identifier (gi) assigned to it. RefSeq records can be distinguished from INSDC records by the inclusion of an underscore (“_”) at the third position of the accession number.

  • $\begingroup$ New sequences are no longer being assigned GI numbers (source) since they were redundant. Use "accession.version" instead, e.g. "NC_000012.12". $\endgroup$
    – mgkrebbs
    Apr 6, 2017 at 20:12

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.