How are residues represented in sequence enumerations according to WIPO Standard ST.26?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

WIPO Standard ST.26 specifies two ways to represent residues in sequence enumerations:

1. Individual representation: Each residue is represented by a name, abbreviation, symbol, or structure. For example, “HHHHHHQ” or “HisHisHisHisHisHisGln”.
2. Shorthand formula: Multiple residues are represented by a condensed notation. For example, “His6Gln”.

As stated in MPEP 2412.02(a):

“WIPO Standard ST.26 specifies that ‘enumeration of its residues’ means ‘disclosure of a sequence in a patent application by listing, in order, each residue of the sequence, wherein [either] (I) the residue is represented by a name, abbreviation, symbol, or structure (e.g., HHHHHHQ or HisHisHisHisHisHisGln); or (ii) multiple residues are represented by a shorthand formula (e.g., His6Gln)’”