During the development of new products, one of the main tests in vitro to be performed is cytotoxicity. However, there are still many doubts about what this test actually accomplishes and that is what we want to explain in the next few lines!

The cytotoxicity test is performed in cell culture and there are specific regulations in the Organization of Economic Co-operation and Development (OECD) and in the International Standards Organization (ISO) about which cells and which protocols are the most suitable for this test. The main question that the cytotoxicity test answers is whether the raw material or the product being tested has the ability to kill the cells or stop these cells from dividing, that is, being harmful for use in humans alive.

There are different ways to assess whether cells are alive or not after contact with the products, the best known of which are: neutral red, 3- (4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide (MTT)

and sulforadamine B. Neutral red, for example, is a vital dye that has the ability to enter cells and stain lysosomes (organelles within cells). Thus, if the product leads to cell death, they will not be stained by neutral red. In order to analyze the results, we must use good controls! That is, a negative control with cells that will remain alive and a positive control, using a reagent that we know will kill the cells. Thus, we will be confident of the test result we are observing.

At Núcleo Vitro, we perform the cytotoxicity test following international regulations of OECD and ISO with strict controls to always bring reliable results to companies. Get in touch to know more and make a budget.