FISH analysis of LAMA84 and LAMA84R cell lines.

(A) Interphase nuclei from LAMA84 displaying 2, 3, and 5 copies of the fused BCR/ABL signal indicating the BCR/ABL chimeric gene. (B) Metaphase spreads in the same cell line showing the modal number of 4 copies of BCR/ABL per cell. In contrast to the single fused signals observed in LAMA84, the resistant LAMA84R line additionally displayed an amplified signal containing multiple copies of BCR/ABL. (C) Interphase nuclei from LAMA84R showing the amplified signal plus single copies of the fused signal. (D) A metaphase sample of LAMA84R shows a similar signal compatible with the amplified element, shown at higher magnification in (E).