Question

• What is the use of LDH assay in toxicity study?

• Describe the principle of LDH assay.

Answer 1

LDH assay is an important microplate assay used for estimation of the toxic potential resulting from chemical compounds or environment toxic factors. It is general indicator of cell and tissue damage.

Principle: lactate dehydrogenase is soluble cytosolic enzyme present in most eukaryotic cells releases into culture medium upon cell death due to damage of plasma membrane.

The increase of LDH activity in culture supernatant is proportional to no. of lysed cells.

LDH activity can hence be used as an indicator of cell membrane integrity and serves as a general means to assess cytotoxicity.

LDH catalyses the reaction between lactate and pyruvic acid. The rate of NADH formation is indicated by increase in absorbance at 340nm and is directly proportional to serum LDH activity.