The LDH assay measures the activity of lactate dehydrogenase, an enzyme found in many tissues, including the heart, liver, and muscles. This assay is commonly used in clinical laboratories to assess tissue damage or disease, as elevated levels of LDH in the blood can indicate cell injury or necrosis. In addition to diagnosing conditions like myocardial infarction and liver disease, the LDH assay can also be used in research settings to study cellular metabolism and the effects of various treatments on cell viability. The test is relatively simple and can provide results quickly, making it a valuable tool in both clinical and research environments.