ABSTRACT
Production of light by tissues is a well-established phenomenon. 1 , 2 The application of the photon counting technique to biological systems (especially in the near infrared region of the spectrum) supplies useful information on oxidative processes in cells and tissues. The technique is sensitive and noninvasive, and it provides continuous monitoring. Several biological models of oxidative stress have been assessed with the low-level chemiluminescence technique to detect formation of excited species and cellular damage; these include models such as hyperoxia, metabolism of hydroperoxides, effect of metal complexes, redox cycling-supported drug metabolism, and enzymatic reactions (see References 2 and 3). Independent of the identification of the electronically excited state(s) responsible for chemiluminescence, it is a highly interesting biological phenomenon in itself.
