Patent ID: 7642085

Claim:
A protein array comprising a polypeptide attached to a solid support, wherein the polypeptide comprises (a) at least a first reactive unnatural amino acid comprising a first side chain comprising a first reactive group, and (b) a second unnatural amino acid comprising a second side chain, wherein the first side chain structure is different from the second side chain structure; wherein the polypeptide comprising the first reactive unnatural amino acid comprising the first side chain comprising the first reactive group and the second unnatural amino acids comprising the second side chain is produced in a cell before attachment to the solid support, wherein the polypeptide is attached to the solid support by a covalent chemical linkage produced by reacting the first reactive group with a second reactive group that is attached to the solid support; and, wherein the second unnatural amino acid in the polypeptide is not reactive with the second reactive group on the solid support; and, wherein the first reactive group comprises an electrophile, a keto or an aldehyde moiety and the second reactive group is a nucleophile moiety; or alternatively, the first reactive group is a nucleophile moiety and the second reactive group comprises and electrophile, a keto or an aldehyde moiety.