Evaluation of hyperthermia effect on cell viability using crystal violet staining, LDH and trypan blue assays

Abstract

There is a variety of techniques for evaluating the viability of cultured mammalian cells. In this study, experimental results of fast cell viability assays were compared to reveal the most suitable method for determination of hyperthermia effect on viability of human breast cancer (MDA-MB 231) and normal liver (WRL-68) cell lines. The cells were exposed to heat at 42°C for 4 different duration of heat exposure (1, 2, 3 and 4 hours); and percentage of cell viability was determined using three different assays (trypan blue (TB), lactate dehydrogenase (LDH) and crystal violet, CV (1% glutaraldehyde or 4% paraformaldehye fixation)). Cell viability by the CV with 1% glutaraldehyde fixation method was not significantly different from those by CV with 4% paraformaldehyde. Crystal violet assay showed less viability of the treated cells meanwhile trypan blue indicated highest viability for both cell lines. Of the three counting techniques, the crystal violet assay gave consistently and significantly higher value than LDH (p<0.03) and trypan blue assay (p<0.05). This proved that crystal violet assay was the most sensitive assay whilst the least sensitive assay was trypan blue exclusion method. Therefore, crystal violet assay was more effective; simple; permits many samples to be analyzed rapidly and simultaneously when compared to LDH and trypan blue assays for MDA-MB 231 and WRL-68 cell lines.