“…PCR products were purified by ethanol precipitation and were used as probes. After hybridization of the biotinlabeled probe on normal human metaphase cells, the slides were treated with anti-biotin Fab' alkaline phosphatase conjugate (1:100; Boehringer Mannheim, Indianapolis, IN) for 45 min at 37°C, and hybridization signals were detected by 3-hydroxy-N-2Ј-biphenyl-2-naphthalenecarboxamide phosphate (Boehringer Mannheim) (Kagiyama et al, 1993). Chromosomes were counterstained with quinacrine plus Hoechst 33258 and observed with a Nikon fluorescence microscope.…”