Viability assay

A viability assay is an assay to determine the ability of organs, cells or tissues to maintain or recover . Viability can be distinguished from the all-or-nothing states of life and death by use of a quantifiable index between 0 and 1 (or 0% and 100%). Viability can assay mechanical activity, motility (spermatozoa or granulocytes), contraction (muscle tissue or cells), mitotic activity, etc.

For example, examining the ratio of potassium to sodium in cells can serve as an index of viability. If the cells do not have high intracellular potassium and low intracellular sodium, then (1) the cell membrane may not be intact, and/or (2) the sodium-potassium pump may not be operating well As with many kinds of viability assays, quantitative measures of physiological function do not indicate whether damage repair and recovery is possible. An assay of the ability of a cell line to adhere and divide may be more indicative of incipient damage than membrane integrity.Fluorescent-based assays do not require large sample sizes. Viability assays are used to assess the success of cryopreservation techniques, the toxicity of substances, or the effectiveness of substances in mitigating effects of toxic substances.

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