Use of a filtration plate in the MTT assay.

The use of the MultiScreen filtration plate enables fluids to be removed efficiently from the plate without disturbing cells, or formazan crystals formed during the MTT test. Using a 1:1 mix of dimethyl sulfoxide and ethanol as solvent allows optical densities to be measured directly on the Multiscreen plate. The possibility of washing cells without losses in their number appears to be advantageous especially for in vitro studies on cytokines and on the cytotoxicity of coloured substances, such as dyes. In this study the results of cytokine assessment using the Multiscreen plate were compared with those obtained using a normal flat-bottomed plate. Two methods of assessment of the cytotoxicity of the dye rose bengal were also compared.