Aberrant chromosomes 15 in SCC cells. (A) Average CGH ratio profiles of chromosomes 15 from SCC-13 and SCL-I and four from SCL-I cells. 4′,6-Diamidino-2-phenylindole-stained normal reference chromosomes, fluorescence ratio images (blue, normal balanced state of chromosome material; red, underrepresentation; and green, overrepresentation in the tumor genome), and idiogram with ratio profiles (left, center, and right vertical lanes represent lower, average, and upper thresholds of the normal range) are shown for each chromosome. Whereas SCC-13 cells show a normal ratio profile of chromosome 15, it is underrepresented in SCL-I cells, as is chromosome 4p. Gray represents chromosomal regions of highly repetitive DNA sequences that are suppressed by Cot I DNA and excluded from evaluation. (B and C) Fluorescence in situ hybridization of metaphase chromosomes. (B) SCC-12 cells (tetraploid) show a translocation chromosome t(13q;15q) (13 in green and 15 in red; upper left corner), two normal copies of chromosomes 15 and 13, an isochromosome [i(13q)], and a translocation chromosome containing material from chromosome 13. (C) SCL-II cells (hypodiploid) contain a translocation chromosome t(1q;15q) (1 in green and 15 in red), one normal copy of chromosomes 15 and 1, and two additional translocation chromosomes containing material from chromosome 1.