What is "accession number"

Accession number may refer to:

• Accession number (bioinformatics), a unique identifier given to a biological polymer sequence (DNA, protein) when it is submitted to a sequence database
• Accession number (library science), the unique number given to each new acquisition as it is entered in the catalog of a library or museum
• Accession number, a unique identifier for an order, used in medical information systems like a laboratory information system (LIS)
  • Accession number, also used in a radiology information system (RIS)

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.

In libraries, art galleries, museums and archives, initial control of an acquisition is usually achieved through assignment of a unique identifier. When used for this purpose, such an identifier is denoted an accession number. Assignment of accession numbers typically occurs at the point of accessioning or cataloging. The term is something of a misnomer, because the form accession numbers take is often alpha-numeric.

If an item is removed from the collection, its number is usually not reused for new items.

In libraries, this numbering system is usually in addition to the library classification number (or alphanumeric code) and to the ISBN or International Standard Book Number assigned by publishers.

Accession numbers are also used by arboreta, botanic gardens, etc., to identify plants.

An accession number may include the year acquired, sometimes the full date (as at the British Museum), and a sequential number separated by a period. In addition, departments or art classifications within the collection or museum may reserve sections of numbers. For example, objects identified by the numbers 11.000 through 11.999 may indicate objects obtained by the museum in 1911; the first 300 numbers might be used to indicate American art, while the next fifty (11.301-350) might be used for African art. In some cases, they also include letters and other punctuation, such as commas, hyphens or slashes.

In older institutions, simpler numbering systems are sometimes maintained alongside, or incorporated within, newer systems. Where the objects are unique, institutions normally need to retain the original number in some form as it will have been used in old references that are still of use in scholarship. In particular, collections of manuscripts use the prefix "MS", and many well known manuscripts are known by their old MS numbers, often incorporating a prefix for a particular collection within a library. These collections may be divided by former owners, as with several British Library "closed" collections, or by language, as with Froissart of Louis of Gruuthuse (BnF MS Fr. 2643-6), indicating a two volume manuscript in French at the .