Interphase fluorescence in situ hybridization (FISH) images of normal and t(9;22) positive nuclei

The dual-color ABL (green) and BCR (red) probes span their respective breakpoint regions, producing two red and two green signals in a normal nucleus (on the left). In the t(9;22) cell (on the right), the single red and green signals correspond to the normal ABL and BCR genes, respectively, while the two yellow-white fusion signals correspond to the Ph chromosome and the reciprocal balanced translocation product (derivative chromosome 9).