[Nucleus DNA content measurement methods features]

We suggest a new theoretical method of the flow cytometry DNA histograms and apply it for Drosophila melanogaster imaginal discs cells. The model gives a possibility to determine the proportions of cells in G1, G2 (M) and S cell cycle phases. We show that the precision of G1 and G2 (M) DNA content measurements is limited by the precision of device zero signal arrangement. The usage of calculated device zero and dividing cells as the DNA content standards may improve the precision of DNA content measurements. We also compared the precisions of different DNA content methods and draw the conclusion that the current precisions of different methods are similar and lie within 2-6% interval.