A lactate dehydrogenase (LDH or LD) is an enzyme found in nearly all living cells (animals, plants, and prokaryotes). LDH catalyzes the conversion of pyruvate to lactate and back, as it converts NADH to NAD+ and back. A dehydrogenase is an enzyme that transfers a hydride from one molecule to another.
This enzyme is useful for enzymatic determination of numerous metabolites, e.g.ATP, ADP, glucose, creatinine, pyruvate, lactate and glycerol, and of enzyme activities, e.g.GPT, PK and CPK when coupled with the related enzymes.
Crystalline suspension in 1.6M ammonium sulfate solution
Enzyme Commission Number
GradeⅡ 2,000U/ml or more
Malate dehydrogenase < 5.0×10⁻²% Pyruvate kinase < 3.0×10⁻²% GPT < 3.0×10⁻²%
pH 6.0-8.0(23°C, 22hr)
2.5×10⁻²M (Lactate), 1.0×10⁻⁴M (Pyruvate)
below 50°C(pH 7.4, 10min)
Stable at 5°C for at least one year
I ‾, Ag⁺, Hg⁺⁺, p-chloromercuribenzoate, LDH inhibitors (formed from NADH)
Lactate dehydrogenase; EC 220.127.116.11; LDH; LD