AST reagent kit GOT-11 series

solutionfor clinical chemistryNAD

For the quantitative determination of Aspartate Aminotransferase (AST) in human serum. METHODOLOGY Karmen developed a kinetic assay procedure in 1955 which was based upon the use of malate dehydrogenase and NADH. Optimized procedures were presented by Henry in 1960 and Amador and Wacker in 1962. These modifications increased accuracy and lowered the effect of interfering substances. The IFCC published a recommended method that included P-5-P in 1978. The present method is based on IFCC recommendations but does not contain P-5-P since most specimens contain adequate amounts of this cofactor for full recovery of AST activity. Principle Aspartate aminotransferase (AST) catalyzes the transfer of the amino group from Laspartate to α-Ketoglutarate to yield oxalacetate and L-glutamate. The oxalacetate undergoes reduction with simultaneous oxidation of NADH to NAD in the malate dehydrogenase (MDH) catalyzed indicator reaction. The resulting rate of decrease in absorbance at 340nm is directly proportional to the AST activity. Lactate dehydrogenase (LDH) is added to prevent interference from endogenous pyruvate which is normally present in serum. REAGENT PREPARATION Prepare working reagent by mixing 4parts of R1 reagent with 1 part R2 reagent.(e.g. 200 µL R1 with 50 µL R2 reagent.) REAGENT DETERIORATION Do not use reagent if: 1. The initial absorbance at 340nm is below 1,0. 2. The reagent fails to meet stated parameters of performance. MATERIALS REQUIRED BUT NOT PROVIDED 1. Accurate pipetting devices. 2. Test tubes/rack. 3. Timer. 4. Spectrophotometer able to read at 340 nm. (UV) 5. Heating bath/block (37°C).