Patent ID: 8030017

Claim:
A thermostable beetle luciferase variant of the luciferase of SEQ ID NO:37, wherein said luciferase variant retains at least 50% activity in aqueous solution for at least 2 hours at a temperature of 50° C. and has up to 42 amino acids modified from SEQ ID NO:37, wherein said modifications comprise a substitution of residue 2 with A, a substitution of residue 91 with I or V, a substitution of residue 183 with Y, a substitution of residue 220 with I or L, a substitution of residue 221 with A, a substitution of residue 249 with M, a substitution of residue 262 with V, a substitution of residue 294 with L, a substitution of residue 353 with N or K, a substitution of residue 354 with N or G, a substitution of residue 386 with P, a substitution of residue 399 with G, a substitution of residue 542 with T, a substitution of residue 543 with N, a substitution of residue 544 with G, and a deletion of residue 545 of SEQ ID NO:37.