When Pharmaceutical companies are developing new therapeutics, it is essential to test the viability and cytotoxicity of those compounds on cells before allowing them to be treated in a clinical setting. A major factor that heavily affects the success of these products is the effectiveness of each pharmaceutical drug. The therapeutic must be effective, but not so effective that it also harms the healthy cells within the body. Cell-based assays are the first step to analyzing the effects of a therapeutic directly on cells and assessing the impact it possesses.
Viability measures the number of live cells, while cytotoxicity measures the toxic quality of a drug on the cells. To determine the proper concentration to use in many desired assays it is important to use dose range and IC50 determination, which are similar to tests used when evaluating viability and cytotoxicity. These two qualities are extremely important when working on therapeutics for clinical research and can both be assessed using a Celltiter-Glo assay.
The therapeutic must be effective, but not so effective that it also harms the healthy cells within the body.
The Celltiter-Glo process uses a 2D or 3D assay of the cell line of interest. For a general 2D assay, the cells are plated, allowed to attach overnight, and treated with various concentrations of the test compounds (typically between a six to eight dose range,) as well as vehicle and media only controls. Cell viability is assessed through the luminescent ATP assay, Celltiter-Glo. The reagent lyses the remaining live cells and creates a luminescence which can be read using a plate reader.
Researchers in Visikol’s Pharmacology and Drug Discovery division are skilled in toxicity assessment and screening in 2D and 3D cellular based assays. The graph’s shown below are the results of two viability and cytotoxicity assessments using A549, lung carcinoma, and HCT-116, colorectal carcinoma, cell lines. Each cell line was treated in triplicate with three different therapeutics separately, Chlorpromazine, Diclofenac, and Paclitaxel. Chlorpromazine is a medicine for schizophrenia, Diclofenac is an anti-inflammatory, and Paclitaxel is a chemotherapy medication. These are all very different therapeutics, each with cytotoxic effects on cells. The cells were seeded, dosed after twenty-four hours with seven doses including vehicle and media only controls, and the Celltiter-Glo assay was performed after seventy-two hours of treatment. Dose, D1, have been the highest concentration and decreasing with each dose. The luminescence value corresponds with the number of live cells at the end of seventy-two hours.
