This symposium brings together several approaches for the detection of specific nucleic acid sequences that have potential applications at the histochemical level.Trask et al. report on the use of fluorescence in situ hybridization (FISH) techniques to study the arrangement of DNA sequences in normal and diseaserelated chromosomes. The sites of specific DNA sequences can be fluorescently tagged. Different sequences can be labeled with different fluorochromes so that their arrangement can be studied using fluorescence microscopy. The distances between points on the same or different chromosomes can be determined in a large number of interphase nuclei or metaphase chromosomes. A variety of probe types, ranging from single-copy sequences to highly repeated sequences can be employed.Hamkalo and co-workers have used non-radioactive methods at the EM level for the detection of nucleic acid sequences by in situ hybridization. Analysis of metaphase chromosomes by electron microscopy allows for high resolution mapping of chromosomes. A variety of labelling procedures have been employed to illustrate the utility of high resolution nucleic acid sequence mapping in these preparations.
High-Resolution Single-Copy Gene Fluorescence in Situ Hybridization and Its Use in the Construction of a Cytogenetic Map of Maize Chromosome 9
