Genetic analysis has been vastly improved by the introduction of the fluorescence in situ hybridization (FISH) procedure. Since 1996, multicolor FISH (mFISH) using whole-chromosome painting libraries as probes has evolved into a powerful technology for detecting interchromosomal changes. Nevertheless, mFISH experiments are not always successful, due to the complexity of the hybridization mix, which requires optimization. Here, we describe the preparative and quality control steps that we have established in our labs in order to obtain consistent results.
