Natural pigment distinguishes between living and dead cells in cultures without damaging them

Researchers have developed a new dye that can be used on cells in toxicology tests when researching new drugs. The study was conducted at the Tokyo Science University, Japan, and is published in the journal Biology.

Scientists know several methods to distinguish living cells from dead ones in toxicological studies, and one of the most popular approaches is “determination of cell viability by dye exclusion method” – DET – using synthetic dyes. In normal DET, a dye such as trypan blue or methylene blue selectively penetrates and stains dead cells, distinguishing them from living ones. However, these synthetic dyes are known to also damage living cells in culture. This makes them unsuitable for long-term research.

Scientists have now discovered an alternative to DET with synthetic dyes: a dye exclusion method using natural pigment made from Monascus purpureus (MP). This is a type of mold traditionally used in Asia for the production of fermented foods.

In a recent study, a team of researchers proved that MP can be used to determine the viability of breast cancer cells. The scientists found that, unlike trypan blue, MP does not damage living cells and is resistant to the typical chemotherapy drug cisplatin. What’s more, it took only ten minutes to stain dead MP cells and is ten times less expensive than trypan blue.