NUCLEIC-ACID SPECIFICITY OF AN ACRIDINE DERIVATIVE PERMITS ITS USE FOR FLOW CYTOMETRIC ANALYSIS OF THE CELL-CYCLE

3-amino-6-methoxy-9-(2-hydroxyethylamine) acridine (AMHA) is an acridi ne derivative, which is easily excited in near ultraviolet and which e mits a bright green fluorescence. The dye was preferentially incorpora ted into nucleic structures as attested by microscopic and cytometric analyses after RNase and DNase treatments. The affinity for RNA seemed low and similar to that observed for propidium iodide. AMHA was quick ly accumulated in fixed cells, and in appropriate concentrations (10-5 0 mu M) was a DNA- and RNA-specific dye. AMHA probably exhibits an ade nine-thymine specificity, as suggested by its quenching after bromodeo xyuridine uptake: the fluorescence quenching was similar to that obtai ned for Hoechst 33258. After cell treatment by RNase and in the presen ce of MgCl2, AMHA staining allowed flow cytometric analysis of the cel l-cycle distribution. The resulting histograms were similar to those o btained with propidium iodide (CV near 3.5%, and similar cell cycle di stribution). Thus, AMHA is a suitable fluorescent dye for efficient an alysis of the cell cycle by flow cytometry. (C) 1997 Wiley-Liss, Inc.