Reverse Chromosome Painting

Chromosome painting refers to the complete decoration of specific metaphase chromosomes with complex probe mixtures. The painting signal is obtained by fluorescence in situ hybridization (FISH) of such mixtures established from a number of different sources (1 –4 ). This technique is a valuable supplemental method in the detailed analysis of specific chromosome aberrations, complex chromosome rearrangements, and chromosomes of poor quality, which have been unresolvable with the traditional chromosome banding techniques. In traditional chromosome painting, complex probe mixtures representing specific chromosomes are hybridized to metaphase spreads containing the chromosome aberration in question. If the hybridized probe mixtures are fluorescence labeled, the composition of the aberrant chromosome is revealed by the distribution of the fluorescence signals obtained with the different probes. The combination of different labeled probes and multicolor techniques simplifies the evaluation.