Karyotype analysis has depended on chromosome banding techniques since their introduction in about 1970, and the information thus obtained is indispensable for the clinical management of patients with hematologic malignancies. Sometimes, however, chromosomal rearrangements involve segments too small, too similarly banded, or too complex to be described adequately or even to be detected by G-banding. Cross-species color banding is a new FISH-based screening technique that enables the generation of a specific color banding pattern for each human chromosome based on the genomic homologies between man and various species of apes. We report the first application of cross-species color banding (RxFISH) to characterize the chromosomal rearrangements of 10 leukemia samples the G-band karyotypes of which were incomplete. The combination of G-banding and RxFISH in every case yielded additional information beyond that obtained by either technique used alone, determining the identity of even the most complex, inter- as well as intrachromosomal, rearrangements. Genes Chromosomes Cancer 26:13-19, 1999.
Copyright 1999 Wiley-Liss, Inc.