ABSTRACT
Conventional cytogenetics and molecular biology have each played impor tant roles in the identification of chromosomal aberrations associated with human disease, particularly malignancies. Nonrandom chromosomal changes often reflect events occurring at the molecular level within the cell and provide important clues about the location of genes involved in these events (1 ,2) . Although traditional chromosomal banding techniques are critical in the assessment of karyotype changes, these techniques have certain inherent limitations that complicate accurate characterization of tumor genomes (3) . These limitations apply particularly to solid tumors and include: (a) difficulty in culturing tumor cells , which typically have a low mitotic index and pro duce chromosomes of poor quality; (b) specimens contaminated by necrotic tissue, making subsequent analyses problematic; (c) the selective growth, in culture, of subclones that may not be representative of the in vivo tumor; and (d) the presence of complex karyotypes, which often precludes reliable, com prehensive identification and characterization of chromosomal abnormalities .
