Example of t(11;14) breakpoint analysis by DNA fiber FISH of the XG-5 cell line.

Red and green bars represent probes detected with Texas Red and FITC, respectively. Overlapping areas of Texas Red– and FITC-stained probes turn into yellow. From top to bottom, the following DNA fibers are shown: (A) a normal 14q32/IgH locus, (B) a normal BCL1/11q13 locus, (C) the 14q+ translocation product containing the cyclin D1 gene as observed in the XG-5 cell line, and (D and E) the 11q-product containing myeov in XG-5. Fibers A through D show hybridization patterns obtained with the standard IgH and 11q13 probe sets as described in “Materials and methods.” Fiber E, representing the 11q-product, shows the hybridization pattern of a combination of IgH and 11q13 probes optimized for visualization of the Eμ-enhancer probe in this particular cell line. For XG-5, this probe set consisted of the 2.7-kb Eμ probe, 11q13 P1 B1587, and IgH cosmid cosIg6.