A look-up table for estimation of the coefficient of variation (CV) during flow cytometry of cellular DNA content distribution was made by a computer simulation of the ahape of the G1 Fluorescence peak. The basic nation is that the accuracy of measurement is indicated by by the sharpness of the G1 fluorescence peak, and in contrast to the well-known FWHM method (full width of the peak at half maximal ordinate value method), it utilizes the height of three channels at the G1 peak