Assessment of a simple, non-toxic Alamar Blue cell survival assay to monitor tomato cell viability

The Alamar Blue (AB) assay, which incorporates a redox indicator that chang es colour or fluorescence in response to metabolic activity, is commonly us ed to assess quantitatively the viability and/or proliferation of mammalian cells and micro-organisms. In this study the AB assay was adapted for the determination of the viability of plant cells. Cell suspension cultures of tomato, Lycopersicon esculentum, L., with differing viabilities, served as the experimental model for a comparison of the AB assay with the convention al 2,3,5-triphenyltetrazolium chloride (TTC) viability assay. The AB assay showed a sigmoidal relationship between cell viability and AB reduction (as quantified by spectrofluorometry or spectrophotometry), which was similar to that obtained using the TTC assay. Both assays detected a significant re duction in cell viability after 48 h exposure to virulent Ralstonia solanac earum (biovar III), while the TTC assay, in addition, revealed cell prolife ration in control cells from 24 to 72 h. The TTC assay detected cell prolif eration over a wider range of cell densities, while the AB assay was more r apid and versatile whilst being non-toxic and thus allowing subsequent cell analysis. Copyright (C) 2001 John Wiley & Sons, Ltd.