Yao-Shan Fan and a panel of senior scientists and pioneering researchers describe in step-by-step style the leading FISH techniques and those molecular technologies beyond FISH available for diagnostic services in genetics and oncology. The methods include labeling FISH probes for DNA and RNA targets, fluorescence genotyping, CGH microarray, spectral karyotyping/multicolor FISH, and primed in situ labeling. There are also techniques for multicolor fiber FISH, multi-telomere FISH, prenatal diagnosis using maternal blood, and preimplantation diagnosis. Oncological methods include simultaneous fluorescence immunophenotyping and FISH for leukemia and lymphoma, HER2 amplification in breast cancer, and CAC/PAC for cancer cytogenetics.