GLYCOLYSIS is one of the major metabolic pathways cells undergo to produce energy and results in the production of pyruvate. One of the eventual fates of pyruvate from this process is lactate dehydrogenase converting it to L-lactate via lactic acid fermentation allowing L-lactate to serve as an indicator of glycolysis. This Glycolysis assay kit is based on measuring the production of L-Lactate from glycolysis in cells. L-Lactate that is secreted into the cell media is quantified using a coupled reaction involving the lactate dehydrogenase catalyzed oxidation of L-lactate that generates pyruvate and NADH which reduces a formazan dye. The intensity of the reduced dye, measured at 565 nm, is directly proportional to the L-lactate concentration in the sample, which in turn is directly proportional to the glycolytic rate of the cells.