Results of the 2-color FISH analysis.

Digoxigenin-labeled BAC clone RP11-706G10 (red signals) and biotinylated Cos 134.8 (green signals) specific to HERV-Kand FGFR1 genes, respectively, were used in the analysis. (A) Metaphase spread from normal lymphocytes showing FISH signals obtained with BAC clone RP11-706G10 (red) on chromosome 19q13.3 and with Cos 134.8 specific to FGFR1 (green) on chromosome 8p12, as expected. (B) Metaphase spread from the patient with the t(8;19) translocation. Chromosomes 8, 19, der 8, and der 19 with hybridizing signals are indicated. Note the red hybridization signals on both der 8 and der 19 chromosomes and their colocalization with FGFR1 signals, indicating that this BAC clone spans the breakpoint. Inset: R banding of the same metaphase. Original magnifications, ×100.