Detection of monosomy in interphase nuclei and identification of marker chromosomes using biotinylated alpha-satellite DNA probes.

Nonradioactive in situ hybridization with chromosome-specific highly repetitive DNA probes is a fast and easy method for the detection of the number of chromosome copies in nonmitotic cells. In this study, we report the use of four biotinylated probes of the human alpha-satellite family recognizing the (peri)centromeric regions of chromosomes 3, 10, 16, and 17. The reliability of the probes was tested by hybridizations to metaphase chromosomes and interphase nuclei of normal blood lymphocytes, which showed a two signal score in 85%-94% and 82%-86% of the cells, respectively. In situ hybridization experiments with nuclei and metaphase spreads derived from the LXFS-650 cell line indicated monosomy for chromosomes 10 and 16 and the presence of two derivative chromosomes 17. These results were in accordance with the cytogenetic data obtained with GTG-banding and confirmed the monoclonality of the cell line. Furthermore, with this method the origin of an unclassified marker chromosome could be identified as a derivative of chromosome 3. Our results show that fluorescence in situ hybridization can be a useful tool in cancer cytogenetics for the detection of numerical aberrations in interphase nuclei and for the classification of marker chromosomes in addition to conventional cytogenetic techniques.