Alamar Blue Assay

The Alamar Blue Assay is a highly cost effective colorimetric method used to measure cell viability and screen for cytotoxicity in tissue culture plates with ninety six wells. Researchers utilize this specific assay to evaluate the overall safety of nanoparticle concentrations by monitoring cellular health. The underlying principle relies on the metabolic reducing activity of living cells. Specifically, cell permeable and nonfluorescent resazurin enters viable cells, where cellular redox enzymes reduce it into highly fluorescent and red resorufin. This reduction process utilizes electron donors like NADH and FADH2. As viable cells continuously convert resazurin to resorufin, the resulting color shift from indigo blue to bright red provides a quantitative measure of cell viability. Students and researchers perform this assay by seeding cells, exposing them to test chemicals, and adding the specific reagent. Finally, a microplate reader measures fluorescence at 590 nanometers, allowing precise calculation of viability percentages for effective screening.