CELL-CYCLE ANALYSIS IN ASYNCHRONOUS CULTURES USING BUDR-HOECHST TECHNIQUE

Modifications of the BUdR[bromodeoxyuridine]-Hoechst technique led to 2 significant findings in human lymphocytes. The 1st is that fluorescence distinguishing chromatids with 0, 1 or 2 BUdR-substituted DNA strands may be visually determined by sequentially staining slides with 2 different concentrations of the Hoechst dye. The 2nd is that use of a pulse-chase BUdR treatment with the sequential staining results in as many as 7 different fluorescent patterns within the cell population. Each of the patterns reflects the number of divisions a cell has undergone both during and after treatment and provides a useful technique for studying the kinetics of a heterogeneous population of dividing cells.