ENHANCED CHEMILUMINESCENT ASSAY FOR ANTIOXIDANT CAPACITY IN BIOLOGICAL-FLUIDS

Enhanced chemiluminescence techniques have been used for several years in the field-of diagnostic immunoassays. We report the use of an enhanced chemiluminescent reaction involving horseradish peroxidase and luminol for the detection of antioxidants and measurement of antioxidant capacity (T.P. Whitehead and G.H.G. Thorpe, UK Patent Application Pub. no. GB2245062, 1991). The addition of solutions of known antioxidants such as ascorbate, urate or vitamin E (or biological fluids containing them) to a glowing chemiluminescent reaction temporarily interrupts light output. Light emission is restored after an interval that is linearly related to the molar quantity of antioxidant added. In this way we have been able to quantify total antioxidant capacity in a variety of biological fluids. A normal range for antioxidant capacity in human serum has been identified and a range of clinical conditions, in which free radical activity is implicated, have been studied.