Quantification of Lactate Dehydrogenase for Cell Viability Testing Using Cell Lines and Primary Cultured Astrocytes

Drug discovery heavily relies on cell viability studies to assess the potential toxicity of drug candidates. L ‐Lactate dehydrogenase (LDH) is a cytoplasmic enzyme that catalyzes the concomitant interconversions of pyruvate to L ‐lactate and NADH to NAD + during glycolysis, and the reverse reactions during the Cori cycle. In response to cellular damage, induced by endogenous cellular mechanisms or as a result of exogenously applied insults, LDH is released from the cytoplasm into the extracellular environment. Its stability in cell culture medium makes it a well‐suited correlate for the presence of damage and toxicity in tissues and cells. We herein present protocols for a reproducible and validated LDH assay optimized for several cell types. In contrast to commercially available LDH assays, often associated with proprietary formulations and high cost, our protocols provide ample opportunities for experiment‐specific optimization with low variability and cost.