Healthy Eating Group

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.

• Application in Drug Screening: These assays are critically important in the pharmaceutical industry to assess the cytotoxicity (cell killing ability) of novel drug candidates and to determine the maximum non-toxic dosage range for further investigation.