DUNS Number - 67-716-4521  |  NCAGE CODE – 2444Y  |  FDA - FEI – 3014694901


Pharma / Bio Pharma

Crop Care




In vitro Skin Irritation

In vitro Skin Irritation

Dermal Irritation in 3D Human Tissue Constructs

TG 439

Skin irritation refers to the production of reversible damage to the skin following the application of a test chemical for uo to 4 hrs. (UN GHS)  3-D reconstructed human epidermal (RHE) tissue constructs  are utilized in this organotypic in vitro model. Tissue viability is determined using the vital dye MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). The reduction of MTT in treated cultures is expressed as a percentage relative to untreated (negative control) cultures.


RHE tissue constructs are made from human epithelial cells, which are differentiate to form a fully differentiated epidermis and a complete functional stratum corneum.


This model allows test materials topical application, so solids, undiluted final formulations, and insoluble test materials can also be tested.


MTT, a vitality-indicating dye, is actively taken up by the tissues and subsequently reduced in the mitochondria of living cells. This chemical reaction produces a purple-colored compound (formazan) within the cells, causing the live tissues to turn deep purple in color. Chemical is identified as a irritant if it causes decrease in cell viability below 50 % threshold.  The extent of reduction in MTT dye is thus used to indentify the skin irritation capacity of test chemical.

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