Lactate dehydrogenase (LDH) is the terminal enzyme of the glycolysis pathway which is widely
found in animals, plants, microorganisms and cultured cells. LDH catalyzes the reversible conversion
of lactate to pyruvic acid with the reduction of NAD+ to NADH and vice versa. According to the different
configuration of catalytic substrate, it could be divided into D-lactate dehydrogenase (D-LDH, EC1.1.1.28)
and L-lactate dehydrogenase (L-LDH, EC1.1.1.27).
NAD+ and lactic acid are oxidized to pyruvic acid by the catalysis of D-LDH. Pyruvate further
reacted with 2,4-dinitrophenylhydrazide to form pyruvate dinitrobenzone, which show brown red color in
alkaline solution and the color depth is proportional to the concentration of pyruvate.
Reagents and Equipment Required but Not Provided:
Spectrophotometer/Microplate reader, constant temperature foster box/water-bath, desk centrifuge,
adjustable pipette, micro glass cuvette/96 well flat-bottom plate, mortar/homogenizer/cell ultrasonic
crusher, ice, distilled water.
