This kit does not use lactate dehydrogenase (LDH) itself, but the measured results are proportional to the concentration of pyruvate generated. Because LDH (in the presence of NADH) can influence the concentration of pyruvate present, the presence of LDH in a sample may influence the assay results.
LDH was not assessed in the development of this kit, but the kit has been used to test serum samples directly. It is recommended to perform several sample dilutions to determine the optimal sample concentration and ensure measured values fall within the linear range of the standard curve. Liver cell and liver-derived cell line lysates are more commonly measured, as serum levels of ALT are normally low. Regardless, considering the effect of LDH on pyruvate in the presence of NADH, a variable concentration of LDH and/or NADH may impact the ALT assay results.