Early luciferase assay reagents required removal of assay components such as medium, serum and test compounds before measuring luminescence. The advent of homogeneous luciferase assays simplified reactions by eliminating the need for media removal prior to luminescence measurement and by enabling light measurement over an extended time period. Now a novel luciferin analog has been developed that enables luciferase assay reagents to operate at a lowered pH. This simple change leads to a reagent that is easier to use, more robust to the reaction environment and less aromatic than reagents containing unmodified luciferin.
Promega Notes 97, 30–32.