Patent ID: 7718389

Claim:
A stabilization composition of coelenterazine or an analog thereof comprising—coelenterazine or its analog of formula (I) wherein, X represents an aralkyl group which may be substituted and is selected from the group consisting of 4-hydroxybenzyl, 4-SO 3 H-benzyl, benzyl and naphthylmethyl groups, or a (cycloalkyl)methyl having 3 to 8 carbon atoms; Y represents an aryl group which may be substituted; Z represents an aralkyl group which may be substituted, a cyclohexylethyl group, an aryl group which may be substituted, a heterocyclic group which may be substituted, or a —CH 2 -heterocyclic group which may be substituted, and an antioxidant selected from the group consisting of ascorbic acid, erythorbic acid and salts thereof, wherein the stabilized composition is suitable for use in a Gaussia luciferase assay.