title: Reduction of MTT to Purple Formazan by Vitamin E Isomers in the Absence of Cells.
abstract: The yellow tetrazolium salt 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) is widely used to determine cell viability in cell proliferation and cytotoxic assays. MTT is reduced by metabolically active cells to form an insoluble purple formazan product that is quantifiable by spectrophotometry. It is the most common and direct assay for cell viability. However, in this present study, we demonstrated that the vitamin E isomers α-β-γ-δ-tocotrienols and α-tocopherol were able to reduce MTT into a formazan product, despite the absence of living cells. For comparison, a second method for determining cell viability, which is the neutral red uptake assay, was used in parallel with the MTT assay. The results showed that neutral red did not interact with the vitamin E isomers. Our findings suggest that the MTT assay is not suitable for studying the proliferative effects of vitamin E isomers on cell growth.
authors: Department of Biosciences, Faculty of Science, The University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia.
authors: Su-Wen
authors: SW
authors: Lim
authors: Department of Biosciences, Faculty of Science, The University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia.
authors: Hwei-San
authors: HS
authors: Loh
authors: School of Biomedical Sciences, Faculty of Science, The University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia.
authors: Kang-Nee
authors: KN
authors: Ting
authors: School of Pharmacy, Centre for Biomolecular Sciences, The University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors: Tracey Dawn
authors: TD
authors: Bradshaw
authors: Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
authors: Zeenathul Nazariah
authors: ZN
authors: Allaudin
keywords: Cell Viability; MTT; Neutral Red Uptake; Vitamin E Isomers