Observation and measurement of cell viability and proliferation is a crucial aspect of many cell-based applications, including cellular imaging, cell culture, functional screening, and drug discovery. Because cellular biology is inherently complex and can be investigated via various parameters, there are similarly many types of cell-based tests and assays. These include assays for live/dead cells, cytotoxicity, apoptosis, mitochondrial membrane potential, reactive oxygen species. Activity of key enzymes involved in cell health can also be tested, such as caspases and dehydrogenases. Use the filters on the left to help narrow down the search for the right cell viability assay.
Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) is a way to detect DNA fragmentation that occurs due to apoptotic signaling cascades. The TUNEL assay relies on nicks being present in the DNA so that terminal deoxynucleotidyl transferase also known as TdT can catalyze the addition of dUTP. This dUTP could be labeled with a hapten or fluorophore so that detection is possible. If you’re looking to detect the later stages of apoptosis, a TUNEL assay kit would be ideal for you.