Characterization of genomic clones by FISH.

(A) FISH analysis of normal cells using cosmid clone S7D, a candidate to span the t(1;14) breakpoint. Biotinylated probes for the chromosome 14 centromere-specific probe and the heterochromatic region of chromosome 1 were cohybridized with digoxigenin dUTP-labeled clone S7D. The centromeric and heterochromatic regions were identified with phycoerythrin-SA (red) and the breakpoint probe with FITC-antidigoxigenin (green). The result confirmed that clone S7D split the breakpoint. (B) FISH analysis of SKI-DLCL-1 cells using P1 PAC clone 35(A12) derived from the normal chromosome 1. The P1 PAC clone 35(A12) probe was labeled with digoxigenin dUTP and detected by FITC-antidigoxigenin. The finding of signals on the normal chromosome 1 and on the der(1) and der(14) chromosomes confirms that P1 spans the region on chromosome 1 involved with the breakpoint.