×

Cytotoxicity Testing

Cytotoxicity tests involve the exposure to cell culture of substances extracted from test material. Cell cultures are extremely sensitive to minute quantities of leachable chemicals and readily display characteristic signs of toxicity in the presence of potentially harmful leachables. Cytotoxicity In Vitro testing is also required to test the biocompatibility of medical devices. Typical testing programs will utilize the ISO test method to meet international regulatory requirements.

Learn More

Agarose Overlay

L-929 mouse fibroblast cells are overlaid with a permeable agar film. A solid sample or liquid saturated disc is then placed in triplicate containers on the agar surface. Cells are examined at 24 hours for signs of toxicity.
L-929 mouse fibroblast cells are overlaid with a permeable agar film. A solid sample or liquid saturated disc is then placed in duplicate containers on the agar surface. Cells are examined at 24 hours for signs of toxicity.

MEM Elution

Solid materials are extracted in cell culture medium and the extracts are then placed in triplicate containers of L-929 mouse fibroblast cells. Cells are examined up to 72 hours for signs of toxicity.
Solid materials are extracted in cell culture medium and the extracts are then placed in duplicate containers of L-929 mouse fibroblast cells. Cells are examined at 24 and 48 hours for signs of toxicity.
If a material is suspected to have cytotoxic properties, performing the cytotoxicity test with dilutions can be useful. Eight 2-fold dilutions are made to determine the toxic endpoint. Performance of the test will result in an estimation of the relative “strength” of the cytotoxic substance in the material.

Quantitative Assays

Solid materials are extracted in cell culture medium. Multiple dilutions of the extract are prepared and added to triplicate wells. After incubation, the MTT reagent {3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide} is added to each well. After a second incubation, the amount of formazan formed is determined. Results are calculated based on the formazan levels.
This assay is used to measure the viability of cells after exposure to a test material extract by measurement of their ability to incorporate and bind neutral red (NR), a supravital dye.
Cytotoxicity screening of biomaterials or medical devices based on colony formation of V79 cells. The V79 lines have a stable growth curve and, as such, a high rate of colony formation; therefore, they are suitable for a screening cytotoxicity test. This assay utilizes the sensitivity of low cell density to evaluate the cytotoxicity of medical devices.

MHLW Testing

MHLW Colony Formation Cytotoxicity using V79 cells
The purpose of this procedure is to evaluate the cytotoxic response of a specified mammalian culture cell line when exposed to an extract of the test article.