Accession number

 A number used to more easily find particular protein sequences in any of the numerous available online databases. Use of an Accession Number speeds up the process of finding a sequence that you have previously found through use of a tool such as BLAST, and allows you find a particular protein without having to do a search that you have done previously. Each protein sequence has its own unique Accession number, meaning that a protein found this way should not be confused with others that are similar.