Abstract: A method for bioassaying for metabolic activation of toxicants from a xenobiotic compound by a metabolic enzyme system includes incubating the xenobiotic compound with a metabolic enzyme system known to produce toxicants during normal metabolic degradation processes and with a mitochondrial membrane preparation competent for enzymatic electron transfer. The production of a toxicant has a detrimental effect upon the electron transfer activity of the mitochondrial membrane preparation which can readily be assayed by observing changes in concentration of a selected redox indicator.

Abstract: A bioassay making use of submitochondrial particles to test for the presence of toxic substances which induce prooxidant states in vivo. The assay uses complex I of the electron transport enzymes on the submitochondrial particles which are capable of donating electrons to the toxicant in solution. The presence of any activated oxygen species in the assay solution is detected spectrophotometrically by the adrenochrome reaction.

Abstract: An assay method is disclosed to test for the presence of toxic substances in environmental samples. The assay uses a suspension of mitochondrial membranes carrying enzymes which can be driven by reverse electron transfer to reduce NAD+ to NADH. The competency of the mitochondrial membrane to accomplish this reduction in the presence of the environmental sample is measured spectrophotometrically to test for toxicants.