A new technique for highly sensitive detection of superoxide dismutase activity by chemiluminescence

A stable enzymatic free radical generation system has been developed which allows a precise production of 02-. and its detection by chemiluminescence between 2 pmol and 8 nmol. This test has been used for assaying superoxide dismutase (SOD) by inhibition of the chemiluminescence (CL) signal. No inhibition was observed with catalase, which excludes the participation of H2O2 in lucigenin CL. N,N-Diethyldithiocarbamate gives 100% inhibition of SOD activity either from a purified enzymatic preparation or from biological samples, which confirms the specificity of the CL assay. SOD assay can be performed either on a purified enzymatic preparation or on biological materials such as cultured cells.