CytoTox 96 Non-Radioactive Cytotoxicity Assay is a colorimetric non-radioactive
cytotoxicity assay. It quantitatively measures lactate dehydrogenase
(LDH), a stable cytosolic enzyme that is released upon cell lysis.
Released LDH in culture supernatants is measured with a 30 to 60 minute
coupled enzymatic assay that results in the conversion of a tetrazolium
salt into a red formazan product. The amount of color formed is proportional
to the number of lysed (dead) cells. Visible wavelength absorbance
data is collected using a standard 96-well plate reader. Thus, the
assay can be used to determine the total number of viable cells in
a given sample.
modified MTT assay works similarly, but uses LDH to determine cell
viability rather than cell death.