Since the nuclear DNA content reflects the position of a cell within a cell cycle, flow cytometric analysis of nuclear DNA content is suitable for cell cycle analysis. In order to determine the fraction of cell population in the G1, S and G2 phases, a DNA content distribution must be deconvolved (most conveniently using a dedicated computer software).
Figure 20. The distribution of nuclear DNA content of nuclei isolated from broad bean meristem root tip cells. A non-parametric curve-fitting method was used for histogram decomposition for cell cycle phases. G1 and G2 peaks are represented by a Gaussian function, and the S phase is represented by a second degree polynomial, broadened with Gaussian function.
In addition to monoparametric (DNA content) analysis, more sophisticated (biparametric) methods have been developed. These are mostly based on incorporation of 5-bromo-2-deoxyuridine into newly synthesized DNA and its detection using a monoclonal antibody or Hoechst fluorescence quenching.
