Patent ID: 7202081

Claim:
Method for simultaneous determination of mammalian cell proliferation inhibition activity and cell toxicity activity of a test substance in a single sample of cells comprising a) contacting a proliferating mammalian cell sample that is present in a predetermined amount with said test substance in at least two different predetermined concentrations; b) contacting said cell sample with a first fluorescence dye that specifically stains either dead cells or viable cells and optionally with a second fluorescence dye staining all cells; c) adding to said cell sample a predetermined amount of latex particles with a size ranging from about 1 to about 20 μm and optionally staining said latex particles with a third fluorescence dye; d) determining ratio of the amount of total cells to the amount of latex particles in said cell sample; e) determining the ratio of step d) and by flow cytometric analysis in said sample the number of dead cells or viable cells to total cells by fluorescence light emitted by said first fluorescence dye at a first wavelength; the number of total cells per volume by scatter light at a first angle or alternatively by fluorescence light emitted by said second fluorescence dye at a second wavelength; the number of latex particles per volume by scatter light at a second angle or alternatively by fluorescence light emitted by said third fluorescence dye at a third wavelength; f) and determining the cell proliferation inhibition activity and toxicity of said test substance by comparing the ratio of viable cells to total cells and the ratio of dead cells to total cells at different concentrations of the test substance.