ABSTRACT
Objective To preparing the reference material(RM) of lactate dehydrogenase(LD),we purification of LD from human erythrocyte(RBC)and studied its properties.Methods Using a modified procedure which including complete hemolysis of the RBC,hydroxyapatite treatment,(NH4)2 SO 4 Precipitation,CM- Sephadex C 50,Sephadex G100 and 5'- AMP- Sepharose 4B affinity chromatography.Results The purified LD has a sepecific activity of 163.0 kU/g protein.It is almost free of contaminating enzymes.Two corresponding bands were observed on both PAG plates stained for either protein or LD activity after electrophresis had been done.The apparent Michaelis constants were of 1.000 and 0.179 mmol/L for L-lactate and NAD and of 0.119 mmol/L 0.062 mmol/L for pyruvate and NADH respectively.Conclusion The final purified LD was found to be very similar to that in human serum in catalytic properties.It is intended to be a fundament to prepare a RM for the measurement of LD.