The Essential Role of Cell Viability Assays in Life Sciences
Cell viability assays are fundamental experimental tools used across drug screening, toxicology, and basic biological research to quantitatively determine the number of live, metabolically active cells in a population.
Principles of Measurement: Assays utilize various markers to assess cellular health:
Metabolic Activity: Assays like the MTT assay measure the ability of living cells' mitochondrial enzymes (dehydrogenases) to convert a non-colored substrate into a detectable product (e.g., purple formazan).
Membrane Integrity: The Trypan Blue exclusion test assesses whether the cell membrane is intact. Living cells exclude the dye, while dead cells with compromised membranes absorb it, staining blue.
ATP Content: Assays can measure the level of intracellular ATP, as ATP is rapidly depleted in dying or dead cells, providing an indicator of energy status.
