Tox7 is a member of Sigma′s CytoToxicity Kit series. It is based on the measurement of lactate dehydrogenase (LDH) release from cells as a measure of cell membrane damage and cytotoxicity. This technique has been utilized as an alternative to 51Cr release for cell mediated cytotoxicity assays, as well as conventional cytotoxicity resulting from interaction of a test material with the cell.
The lactate dehydrogenase assay is a means of measuring either the number of cells via total cytoplasmic lactate dehydrogenase (LDH) or membrane integrity as a function of the amount of cytoplasmic LDH released into the medium. This method is simple, accurate and yields reproducible results. The assay is based on the reduction of NAD by LDH. The resulting reduced NAD (NADH) is utilized in the stoichiometric conversion of a tetrazolium dye to a soluble, colored formazan derivative.