CytoTox 96® Non-Radioactive Cytotoxicity Assay Technical Bulletin
Literature # TB163
The CytoTox 96® Non-Radioactive Cytotoxicity Assay is a colorimetric alternative to 51Cr release cytotoxicity assays. The CytoTox 96® Assay quantitatively measures lactate dehydrogenase (LDH), a stable cytosolic enzyme that is released upon cell lysis, in much the same way as 51Cr is released in radioactive assays. Released LDH in culture supernatants is measured with a 30-minute coupled enzymatic assay, which results in conversion of a tetrazolium salt (INT) into a red formazan product. The amount of color formed is proportional to the number of lysed cells. Visible wavelength absorbance data are collected using a standard 96-well plate reader. Methods for quantifying LDH using tetrazolium salts in conjunction with diaphorase or alternate electron acceptors have been used for several years. Variations on this technology have been reported for measuring natural cytotoxicity, and results are identical (within experimental error) to values determined in parallel 51Cr release assays.
Printed in USA. Revised 12/12.