Efficiency of MTT and Trypan Blue Assays for Detection of Viability and Recovery of Different Frozen Cell Lines

Abstract

HE quantity of healthy cells in a sample is known as cell viability. For all types of cell culture, measuring cell viability is crucial to ensuring a supply of high-quality cell lines through setup, preparation and storage. Although the cryopreservation technique is used in both scientific and clinical research, there are still certain restrictions. At low temperatures, such as −196 °C (i.e., in liquid nitrogen) cells metabolize is almost nothing, which has unavoidable side effects, such as a genetic drift toward biological variations of cell-associated changes in lipids and proteins that could impair cellular activity and structure. Also, cells can be harmed by cryoprotective agents (CPAs), especially when they were administered in high concentrations in conditions where they would typically be used. So, it is important to use a reliable technique to follow up changes affecting cell viability after cryopreservation which were compared with control freshly subcultured cells. In the present study, the MTT assay was used to correlate cell behavior according to the number of healthy and viable cells. Different kinds of cell cultures were cryopreserved with dimethyl sulfoxide (DMSO) at 10% for variable years in a liquid nitrogen tank (-196 °C). Then, different samples were tested for viability using the MTT assay and counted by the trypan blue assay for comparing both results accuracy and confirmed by visual examination in sub-cultured media twenty four hours post-thawing. The MTT assay was easy, fast and showed more accurate results than the trypan blue assay. The visual examination twenty four hours post-subculture indicated that MTT assay can differentiate between healthy and apparently viable cells which have lost their function whereas the trypan blue assay failed to detect healthy cells in some samples.