Two-cell-divisions-BrdU-pulse-chase Analysis in Human Ovarian Cancer Cells at Two Different Growth Statuses
To analyze cell cycle progression dynamically and in detail, a new method was proposed using a modified bromodeoxyuridine (BrdU)-pulse-chase method with a flow cytometer. The method was used to analyze cell cycle progression of two cell divisions in BG -1 human ovarian cells at two different cell growth statuses, initially plated at 1 × 106 or 3×106. In this study, cells pulse-labeled with BrdU were divided into six compartments in the S phase; i.e., two segments for BrdU content correspondent to half of the highest channel number and three segments for DNA content correspondent to the G1, S and G2/M phases. This division is based on the theory that BrdU content is reduced to half after one cell division. The labeled-cell progression was observed from compartment to compartment. Then this method was compared with the analysis of DNA histograms and conventional BrdU-pulse-chase methods. Detailed cell progression could be identified with the present method more dynamically than with DNA histograms or conventional BrdU-pulse-chase methods, and two different growth statuses could also be distinguished. Therefore, this two-cell-divisions-BrdU-pulse-chase method may facilitate the analysis of complicated alterations of cell cycle progression.