Patent ID: 6998229

Claim:
A method for determining the presence of a glucuronide in a sample, comprising: (a) binding a glucuronide repressor to a nucleic acid molecule comprising a glucuronide operator to form a complex; wherein the glucuronide repressor comprises the amino acid sequence of SEQ ID No: 2 or a variant thereof, wherein said variant is encoded by the complement of a nucleic acid molecule that hybridizes with SEQ ID No: 1 under stringent conditions and wherein said glucuronide repressor and said variant binds both the glucuronide operator and a glucuronide; (b) contacting the complex with a sample containing the glucuronide, wherein the glucuronide binds to the repressor protein causing release of the repressor protein from the nucleic acid molecule; and (c) detecting repressor protein that has been released.