Amplite? Colorimetric D-Lactate Dehydrogenase (LDH) Assay Kit . Lactate dehydrogenase (LDH) is an oxidoreductase enzyme that catalyzes the interconversion of pyruvate and lactate. LDH is present in cytosol of a wide variety of organisms, including animals and plants. Cells release LDH into the bloodstream after tissue damage or red blood cell hemolysis. Since LDH is a fairly stable enzyme, it has been widely used to evaluate the presence of damage and toxicity of tissue and cells. Quantification of LDH has a broad range of applications. LDH is also elevated in certain pathological conditions such as cancer. This Amplite? Lactate Dehydrogenase Assay Kit provides an absorption-based method for detecting D-lactate dehydrogenase (D-LDH) in biological samples such as serum, plasma, urine, as well as in cell culture samples. In the enzyme coupled assay, LDH is proportionally related to the concentration of NADH that is specifically monitored by a chromogenic NADH sensor. This assay is specific for D-LDH. The absorption signal can be read by an absorption microplate reader at the absorbance ratio of ~570 nm to ~605 nm (A575 nm/A605 nm). With this colorimetric Amplite? D-lactate Dehydrogenase Assay Kit, we were able to detect as little as 3 mU/mL D-lactate dehydrogenase in a 100 μL reaction volume.