How does the MPEP define standard amino acids?

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.

While the MPEP doesn’t directly define standard amino acids, it indirectly provides this information by referencing WIPO Standard ST.26. According to MPEP 2412.03(c):

WIPO Standard ST.26, paragraph 3(e), identifies “modified amino acid” to mean any amino acid as described in the definition of “amino acid”, other than L-alanine, L-arginine, L-asparagine, L-aspartic acid, L-cysteine, L-glutamine, L-glutamic acid, L-glycine, L-histidine, L-isoleucine, L-leucine, L-lysine, L-methionine, L-phenylalanine, L-proline, L-pyrrolysine, L-serine, L-selenocysteine, L-threonine, L-tryptophan, L-tyrosine, or L-valine.

By inference, these 22 amino acids listed are considered the standard amino acids. This includes the 20 common amino acids plus pyrrolysine and selenocysteine.