Fluorescence In situ hybridization (FISH) as a tool for the detection of significant chromosomal abnormalities in childhood leukaemia.

Cytogenetics is integral to the diagnosis of childhood leukaemia, particularly in relation to the risk stratification of patients for treatment. Fluorescence in situ hybridization (FISH) has become an important complementary technique, expanding chromosomal analysis into the molecular arena. It has greatly improved the accuracy and applicability of cytogenetics and led to the discovery of novel chromosomal changes of prognostic significance. Many probes are now commercially available, providing robust and reliable detection of chromosomal abnormalities. Since the cloning of the human genome, it is now possible to access detailed genomic information and develop FISH probes for virtually any known DNA sequence. The range of procedures necessary for the successful application of FISH in the accurate detection of significant chromosomal abnormalities in childhood acute leukaemia is described here.