Linearity Comparison of Three Colorimetric Cytotoxicity Assays

摘要

Cell viability assays, including techniques to assess the proliferation of cancer cell lines, constitute a rapid, inexpensive and sensitive screening method to pre-clinically evaluate the activity of a potential drug or substance. This study investigates and compares seeding densities and linearity of three such methods: MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide), SRB (sulforhodamine B) and CVE (crystal violet elution) assays. SRB and CVE are staining assays for proteins, while MTT measures the mitochondrial activity of living cells. Assays were performed on five cancer cell lines, A375, PC3, DU145, HCT116 and COR-L105, and the coefficient of determination (R2) was employed to determine fit into a linear regression model. The results show that CVE is the most linear assay at fixed time points. SRB at 515 nm is better for measurements over time. Seeding densities between 9000 and 12,000 were the optimum. However, seeding densities and doubling times should be taken into consideration when designing an experiment.