The CyQUANT LDH Cytotoxicity Assay provides a simple and reliable colorimetric assay for cytotoxicity. Lactate dehydrogenase (LDH) is a cytosolic enzyme present in many different cell types and is released into the cell culture medium upon plasma membrane damage. The CyQUANT LDH Cytotoxicity Assay provides reagents for accurate and quantitative measurement of these extracellular LDH.

Note: The CyQUANT LDH Cytotoxicity Assay Kit (Cat. No. C20300 and C20301) is a direct replacement for the Pierce LDH Cytotoxicity Assay Kit (Cat. No. 88953 and 88954).

Features of the CyQUANT LDH cytotoxicity assay include:
•Convenience—Add-mix-detect method, suitable for adherent and suspension cells, including 3D cell models
•Accurate—Provides quantitative measurement of LDH release
•Flexible—Suitable for high-throughput screening, monitoring changes in cytotoxicity over time in the same sample
•Robust—Using Stable LDH Enzyme Activity as a Cytotoxicity Marker

LDH is a cytosolic enzyme present in many different cell types and is a well-established and Reliable indicator of cytotoxicity. Cell membrane damage results in the release of LDH into the surrounding cell culture medium. These extracellular LDH can be quantified by a coupled enzymatic reaction in which LDH catalyzes the conversion of lactate to pyruvate by reducing NAD+ to NADH. Diaphorase then uses NADH to reduce the tetrazolium salt (INT) to a red formazan product that can be measured at a wavelength of 490 nm. The level of formazan formation is directly proportional to the amount of LDH released into the culture medium.

The CyQUANT LDH Cytotoxicity Assay provides the reagents needed for this simple and reliable colorimetric assay of cytotoxicity. The kit can be used on different cell types, including 3D cell models, to detect both chemical compound-mediated and cell-mediated cytotoxicity. Because LDH in the culture medium is used as an indicator of cytotoxicity, this assay can be used to monitor changes in cytotoxicity over time in the same sample. To perform an analysis, transfer an amount of cell culture medium to a new microplate and add the reaction mixture. After incubation for 30 minutes, stop the reaction by adding stop solution, and then measure the absorbance using a microplate reader.