Analysis of Radiation-Induced Chromosome Exchanges Using Combinatorial Chromosome Painting

Combinatorial chromosome painting techniques such as multiplex fluorescence in situ hybridization (mFISH) or Spectral Karyotyping (SKY) follow basic fluorescence in situ hybridization (FISH) procedures but use combinations of fluorochromes to label probes to specific chromosomes in such a way that each chromosome is painted with a unique signal. Such signals are captured with image analysis systems allowing the construction of karyotypes with each chromosome unambiguously identified. These systems allow chromosomal analysis in great detail and are particularly useful for the detection of complex chromosome exchanges that originate from three or more breaks. This chapter will describe methods that can be used to analyze the results obtained in mFISH karyotypes particularly with relation to complex chromosome exchanges.