Lactate dehydrogenase (LDH) is an oxidoreductase enzyme that catalyzes the interconversion of pyruvate and lactate. Localized in the cytosol, LDH is present in 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.

AAT Bioquest's Amplite^® Lactate Dehydrogenase Assay Kits provide both fluorescence- and absorbance-based methods for detecting either L-lactate dehydrogenase (L-LDH) or D-lactate dehydrogenase (D-LDH). In the enzyme coupled assay, LDH is proportionally related to the concentration of NADH that is specifically monitored using a fluorogenic NADH sensor. The fluorescence signal can be read using a fluorescence microplate reader at Ex/Em = 540 nm/590 nm. We were able to detect as low as 1 mU/mL L-LDH in a 100 µL reaction volume. The assays are robust, and can be readily adapted for a wide variety of applications that require the measurement of L-LDH.