Amino acids codes (symbols) are listed below (1 and 3 letters codes). Approved nomenclature for reports is the 3 letters code:
| Amino acid | Code (1 letter) | Code (3 letters) (official) |
| Alanine | A | Ala |
| Arginine | R | Arg |
| Asparagine | N | Asn |
| Aspartic Acid | D | Asp |
| Cysteine | C | Cys |
| Glutamic Acid | E | Glu |
| Glutamine | Q | Gln |
| Glicine | G | Gly |
| Histidine | H | His |
| lsoleucine | I | Ile |
| Leucine | L | Leu |
| Lysine | K | Lys |
| Methionine | M | Met |
| Phenylalanine | F | Phe |
| Proline | P | Pro |
| Serine | S | Ser |
| Threonine | T | Thr |
| Tryptophan | W | Trp |
| Tyrosine | Y | Tyr |
| Valine | V | Val |
| Asn + Asp | B | Asx |
| Gln + Glu | Z | Glx |