exploits endogenous signal responses. The measurement of luminescence, i.e., emission
of absorbed energy as light that results from a chemical reaction (chemiluminescence)
or a physiological process (bioluminescence), is used routinely in biomedical
research in a wide range of assays. Many organisms ranging from bacteria
to
Þsh and Þreßies have the ability to emit light. The chemical reaction resulting in
bioluminescence is due to the presence of an oxygenase that catalyzes the oxygenation
of the substrate (a luciferin) to produce a molecule in an electronically excited
state. In
Þreßies, for example, luciferase uses molecular oxygen and ATP to produce