Cytotoxicity test

In vitro cytotoxicity tests are tests that are used to evaluate the effects of substances on living cells outside the body. These tests are important for the biological evaluation of medical devices, drugs, pesticides and other chemicals. These tests can help determine whether a substance is toxic, irritating or sensitizing to cells. These tests can also help study the mechanisms of action of substances at the cellular level.

In Vitro Cytotoxicity Test

In vitro cytotoxicity tests can be subdivided into quantitative and qualitative tests, and further subdivided according to the method used to observe the cytotoxic effect. Ultimately, each test boils down to the calculation or estimation of the lD50 value for a given active substance, i.e. the concentration at which 50% of the cells tested are destroyed.

There are many types of quantitative cytotoxicity tests that differ in detection methods, cell systems and evaluation parameters. Some of the most commonly used tests are:

MTT test

involves measuring the amount of formazan, which is a product of the reduction of tetrazolium salt by mitochondrial enzymes of cells. Formazan is insoluble and dark blue in colour. The more living and metabolically active cells are in culture, the more formazan is produced and the greater the absorbance of light through the sample. Absorbance can be measured with a spectrophotometer or plate reader.

Trypan blue test

involves measuring the number of cells stained with trypan blue, which is a positively charged dye. This dye does not enter living cells, but penetrates dead or damaged cells, staining them blue. Cells stained with trypan blue are counted under a microscope or automatic cell counter.

Propidium iodide test

involves measuring the fluorescence of propidium iodide, which is a fluorescent dye. This dye penetrates inside dead cells and intercalates with nucleic acids, showing red fluorescence. Fluorescence can be measured using a flow cytometer or plate reader.

Cytotoxicity test according to EN ISO 10993-5

is based on the international standard ISO 10993-5, which was developed by the International Organisation for Standardisation (ISO). This standard has also been adopted as the European standard EN ISO 10993-5 and has been in force in Poland since 2009. This standard complies with the requirements of Regulation (EU) 2017/745 on medical devices.

Cytotoxicity testing according to EN ISO 10993-5 is an in vitro test that is part of the biological evaluation of medical devices. The purpose of this test is to check whether substances contained in medical devices can damage human or animal cells. This test is important for assessing the safety and efficacy of medical devices such as implants, dressings, syringes, catheters, etc.

Badanie wg PN-EN ISO 10993-5 polega na przygotowaniu ekstraktu z badanej substancji i narażeniu na niego komórek hodowanych w laboratorium. Komórki mogą być pochodzenia ludzkiego lub zwierzęcego, w zależności od celu badania. Następnie ocenia się wpływ ekstraktu na żywotność, metabolizm lub błonę komórkową komórek. Można stosować różne metody pomiaru cytotoksyczności, takie jak test MTT, test NRU, test LDH lub test XTT. Wyniki badania są wyrażane jako procentowa zmiana żywotności komórek w porównaniu z kontrolą.

Please contact our Customer Service Office regarding cytotoxicity tests at 71 738 20 25 or biuro@ekolabos.pl