Evaluating array-CGH based clustering of tumors

DNA preparation to cancer profiles •Many of the changes in the genome associated to cancer can be seen by making gene copy number measurements. Increased copy numbers of genes are associated with oncogenes and decreased copy numbers are associated with tumor suppressor genes. •Array-based Comparative Genomic Hybridization (arrayCGH), introduced in the late nineties, allows efficient characterization of subchromosomal gains and losses(1). • Tumoral and normal DNA are hybridized together and are differentially marked with red and green fluorescence. From the image of the slide, the intensity of the ratio tumoral/normal DNA is measured. Normal copy number equals two every where in the genome.