Low-level luminescence from microsomes exposed to enzymatic systems that generate triplet species.

Microsomes exposed to the propanal/horseradish peroxidase/O2 system develop a weak chemiluminescence. The underlying process is distinct from that occurring during lipid peroxidation because the emission intensity peaks at around 560 nm, rather than in the red, and no malonaldehyde is formed. Triplet acetaldehyde appears to be responsible for the induction of the process, which in turn leads to excitation of a component in microsomes, possibly a flavoprotein.