The enzymatic assay of pyruvic and lactic acids. A definitive procedure

An investigation of the enzymatic assay of pyruvic and lactic acids was undertaken to establish conditions for a stable equilibrium, as seen spectrophotometrically, which approximates a complete reaction in the appropriate direction. These conditions were employed to develop a definitive assay for the above acids using the known absorption coefficient for DPNH at 340 Mμ, thereby eliminating the need either for standard solutions or for estimating endogenous rates. The procedures are described in detail.