Estimation of succinic acid in biological materials

Abstract

A spectrophotometric method for the estimation of from 0[center dot]02 to 0[center dot]20 [mu]mole of succinate is described. It is based on the reduction of 26-dichlorophenol-indophenol by succinate in the presence of succinic dehydrogenase. Both succinate and [alpha]-oxoglutarate reduce the dye enzymically under the assay conditions whereas pyruvate does not. Interference by [alpha]-oxoglutarate may be prevented by a preliminary incubation with semicarbazide. The advantages of the method are its sensitivity and the ease of preparation of the succinic dehydrogenase. Application of the method to biological material showed that rat tissues contained between 0.15 and 1[center dot]10 [mu]moles of succinic acid/g. wet wt. Washed cells of Rhodopseudomonas spheroides contained 10[center dot]5 [mu]m-moles/mg. dry wt.