This method measures the leakage of DNA and lactate dehydrogenase (LDH, EC. 1.1.1 27) from lymphocytes into the surrounding medium as an indicator of cytotoxicity. This method also includes an assay of intracellular (mitochondrial) diaphorase as a measure of cellular activity (MTT assay).

http://embryo.ib.amwaw.edu.pl/invittox/prot/6.htm