Limitations of MTT and CCK-8 assay for evaluation of graphene cytotoxicity

Cellular toxicity test is a key step in assessing the graphene toxicity for its biomedical applications. In this study, we investigated the cytotoxicity of graphene with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2Htetrazolium bromide (MTT) and tetrazolium-8-[2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4disulfophenyl)-2H-tetrazolium] monosodium salt (CCK-8) assay on HepG2 cell line and Chang liver cell line. The cell viability data obtained by using MTT and CCK-8 assay showed inconsistent. Graphene induced adsorption, optical interferences, as well as electron transfer can prevent to appropriate evaluate graphene toxicity. Our findings demonstrated the importance of careful interpreting of obtained data from classical in vitro assays on assessment of graphene cytotoxicity.