fluorescent in situ hybridization is a molecular diagnostic technique that utilizes labeled DNA probes to detect or confirm gene or chromosome abnormalities. fluorescent in situ hybridization is often utilized for both research and diagnosis of hematological malignancies and solid tumors. Conceptually, fluorescent in situ hybridization is a very straightforward technique whereby a DNA probe is hybridized to its complementary sequence on chromosomal preparations previously fixed on microscope slides . fluorescent in situ hybridization is able to detect cells that have chromosomal abnormalities consistent with neoplasia .