[51] Chromosomal fine mapping of apolipoprotein genes by in situ nucleic acid hybridization to metaphase chromosomes

Publisher Summary Molecular cloning of specific apolipoprotein genes has accelerated the mapping of apolipoprotein genes considerably, and constitute an important tool for mapping apolipoprotein genes. This chapter describes the in situ nucleic acid hybridization to mitotic chromosome preparations that has been developed recently to localize single copy genes such as apolipoprotein genes. This method is rapid, generally allows higher resolution, and is a powerful tool for fine chromosomal gene mapping. However, single- or low-copy genes, such as structural genes for apolipoproteins, could not be detected. In applying this approach to the detection of single-copy sequences on human mitotic chromosomes, cloned sequences are labeled with [ 3 H]dNTPs, and the method is now a powerful tool for localizing single-copy and low-repeat DNA sequences in normal cells as well as in cells with abnormal karyotypes. The chapter also discusses 3 H labeling of DNA probes by nick-translation, autoradiography, G-banding, and data analysis.