FISH analysis of Ph-positive metaphase cells.

(A) Triple-probe/3-color signal pattern observed in a Ph-positive metaphase cell with no detectable deletion of chromosome 9 sequences.ABL is in red, BCR in green, and ASS in blue. A colocalized red/green signal marks the Ph chromosome, the der(9) chromosome is identified by a single blue signal, the normal 22 by a green signal, and the normal 9 by a blue/red doublet. (B) Triple-probe/3-color signal pattern in a Ph-positive metaphase cell with a deletion of chromosome 9 sequences. The der(9) chromosome does not show a blue ASS signal (arrow). (C) D-FISH signal pattern in a Ph-positive metaphase cell with no detectable loss of chromosome 9 or 22 sequences. ABL is in green and BCR in red. A colocalized red/green signal marks both the Ph and der(9) chromosomes, a green signal identifies the normal 9, and a red signal marks the normal 22. (D) D-FISH signal pattern in Ph-positive metaphase with loss of sequences from chromosome 9 and 22. ABL is in green andBCR in red. There is a colocalized red/green signal on the Ph chromosome but not on the der(9) (arrow).