Patent ID: 7560245

Claim:
A luciferase protein that retains more than 85% of its luciferase activity in 0.1% benzalkonium chloride compared to its luciferase activity in the absence of benzalkonium chloride produced by a process comprising: culturing a bacterium comprising a polynucleotide that encodes a luciferase protein that retains more than 85% of its luciferase activity in 0.1% benzalkonium chloride compared to its luciferase activity in the absence of benzalkonium chloride that is obtained by substituting the gene portion of the wild type firefly luciferase with a product of amplification of a template nucleic acid prepared from GENJI firefly or HEIKE firefly using the oligonucleotide primers having the sequence of SEQ ID NOs: 1 and 2 and recovering from the culture said luciferase protein.