The ToxiLight™ BioAssay Kit is a bioluminescent, non-destructive cytolysis assay kit designed to measure the release of the enzyme, adenylate kinase (AK), from damaged cells. AK is a robust protein present in all eukaryotic cells, which is released into the culture medium when cells die. The enzyme actively phosphorylates ADP to form ATP and the resultant ATP is then measured using the bioluminescent firefly luciferase reaction.

As the level of cytolysis increases, the amount of AK in the supernatant also increases, which results in emission of higher light intensity by the ToxiLight™ reagent. Because the ToxiLight™ BioAssay Kit exploits the fact that AK is released from cells when they die, there is no need for cell lysis (unlike many other cytotoxicity assays). Repeated samples of supernatant can therefore be taken over time without disrupting the cells themselves. This allows for kinetic analysis of cell death.

The ToxiLight™ BioAssay Kit also facilitates high content screening by allowing other tests to be performed on the original cells.

All the components required for AK detection are contained within a single reagent making the assay very simple to perform. The kit provides outstanding sensitivity with a detection limit of 10 cells per microwell with a dynamic range of over 5 orders of magnitude. Extended signal stability also makes the assay suitable for batch processing in high-throughput screening applications.

• Highly sensitive - the ToxiLight™ BioAssay Kit exploits the cyclic nature of the AK reaction whereby a small amount of the AK enzyme can generate high concentrations of ATP. This enables the detection of very subtle changes in cytotoxicity and reduces false negatives
• Non-destructive - ToxiLight™ assay detects cellular AK present in cell culture supernatants, eliminating the need to lyse cells to perform the assay, and allowing multiple tests to be performed on the same sample
• Simple - assay requires the simple addition of a single reagent, which can be added directly to wells in which cells are growing, or to a small sample of aspirated culture supernatant
• Fast - readable signal is detectable 5 minutes after the addition of the ToxiLight™ BioAssay reagent
• Flexible - cell supernatants can be frozen with no loss of AK activity, allowing for long-term kinetic studies
• Safe - no hazardous chemicals are required