The aim of this study was to provide a practical FD-FCM method. Peripheral blood (PB) erythrocytes and bone marrow (BM) erythrocytes were obtained from rats treated with
cyclophosphamide at a dose of 20 mg/kg for two days. Nucleic cells of BM samples were eliminated using
a cellulose column. Then erythrocytes were fixed, stained with Hoechst 33258 and PI and examined with
FCM. Mean FD-FCM values of micronucleated immature erythrocytes in PB and BM were respectively
110% and 77% of the values obtained by microscopy. Percentages of mean immature erythrocyte values
by FCM to those by microscopy were 74% and 94%. These data suggest that the simple method, composed
of column purification of erythrocytes, methanol fixation, fluorescent dye staining and FCM, was useful
for automated scoring in micronucleus testing of rat BM and PB.