a) Microarray genomic values for chromsome 20. Note that the entire chromosome 20 has been gained and that, as CGH reveals, a peak of amplification is found at 20p. b) FISH with BAC RP11-243J16 (labeled in green) containing ID1 and BCLX genes to confirm genomic data; c) Graphical representation of microarray genomic (blue) and expression (pink) values as a function of gene position; d) FISH with BAC RP11-314N13 (labeled in red) containing FKBP1A gene on chromosome 20. Metaphase spreads from huT78 cells were prepared by standard cytogenetic methods. Gene-specific BAC clones were selected from the EnsEMBL database. Clones were labeled with SpectrumGreen-dUTP or SpectrumOrange-dUTP (Vysis) by nick translation. Dual-color hybridizations were performed at 37°C for 14–16 h and slides were washed and examined using an Olimpus AX60 epifluorescence microscope. The specificity and location of each probe was previously confirmed by FISH on normal metaphases prior to hybridization on huT78 cells.