Lactate Dehydrogenase (LDH) Cytotoxicity Assay Kit

Also known as the Lactate Dehydrogenase Leakage Assay Kit or LDH Release Assay Kit. By measuring LDH activity or leakage in cell culture supernatants, it assesses drug-induced cytotoxicity.

Lactate dehydrogenase (LDH or LD) is a stable protein found in the cytoplasm of healthy cells. Under normal conditions, it cannot cross the cell membrane; however, when cells are damaged, increased membrane permeability causes LDH to leak into the extracellular space. As intracellular LDH levels drop, culture medium LDH levels rise. Measuring LDH activity or leakage rate in the culture medium reflects drug-induced cytotoxicity. LDH belongs to the oxidoreductase family and catalyzes the reversible oxidation-reduction reaction between lactate (L) and pyruvate (P). The reaction equation is: Lactate + NAD⁺ → Pyruvate + NADH + H⁺, where L→P represents the forward reaction and P→L represents the reverse reaction.

Lactate Dehydrogenase (LDH) Cytotoxicity Assay Kit. Principle: NAD serves as the hydrogen acceptor. LDH catalyzes the conversion of lactate to pyruvate, which then reacts with dinitrophenylhydrazine to form pyruvate dinitrophenylhydrazone. In an alkaline solution, this product appears brownish-red; its intensity is proportional to the pyruvate concentration and can be measured at 440 nm using a microplate reader. LDH activity released during cytotoxicity or present in other samples is calculated using the provided formula. This kit is suitable for routine LDH activity assays and is primarily used for cell toxicity detection based on LDH release. For research use only. Not intended for clinical diagnosis or other applications.