Firefly luciferase as a reporter to study gene expression in Streptococcus mutans.

The utility of firefly luciferase as a reporter was tested in Streptococcus mutans. Under control of an endogenous promoter, the luciferase coding sequence was strongly expressed, while a promoterless version was indistinguishable from the background. Luciferase activity was easily extracted and the assay rapid and reproducible. In addition, the half-life of luciferase activity was found to be comparable to those of other frequently used reporters. Thus, firefly luciferase can readily be used as a reporter in S. mutans, a useful alternative to methods requiring radioactive isotopes.