How does the MPEP define standard amino acids?

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.

To learn more:

• standard amino acids
• WIPO Standard ST.26
• patent application
• sequence disclosure