Lactate dehydrogenase (LDH, LD) is a stable cytoplasmic enzyme present in most cells. During damage to (or rupture of) cell cytoplasmic membranes, LDH is released from cells and into the surrounding cell culture supernatant. Quantitation of LDH in cell culture supernatant is one method by which investigators analyze cell death levels.
The LDH Cytotoxicity Detection Kit is a simple yet sensitive, non-radioactive 96-well assay intended for the detection of lactate dehydrogenase (LDH, LD) that is released from damaged cells and into the cell culture supernatant. Via this kit, the LDH that is present in the surrounding cell culture medium participates in a coupled reaction that converts yellow tetrazolium salt (INT) into a red formazan product. The amount of LDH enzyme activity, measured as a 490/492 nm absorbance reading on a microplate reader, directly correlates with the number of damaged cells in culture. The entire assay procedure, which includes cell growth, chemical reaction and absorbance measurement, is performed in a single 96-well plate.