Hybridization techniques, diagnostic

A diagnostic method using fluorescence labeled DNA probes to detect and quantify the number complementary chromosomal sequences on a cellular resolution. A related technique that also allows assessment of gene amplifications, but without precise quantification of copy numbers is the chromogenic in situ hybridization (CISH). Here, instead of a fluorescent dye an enzyme that can generate a colored precipitate in the tissue samples is coupled to the DNA probe. 

Chan, A., Coupling different molecular techniques onto a porous microarray for diagnostic applications Detection of deletions and duplications in Duch-enne muscular dystrophy (DMD) using multiplexed amplifiable probe hybridization (MAPH) on PamChip , First International Conference on Microarrays for Diagnostics, San Diego, CA, March 21-22, 2002. 

Hybridization of nucleic acid probes to membrane-bound target sequences is a commonly used technique in gene structure and expression analysis, medical diagnostics, and gene targeting. 

The development of assay techniques that have convenience of solid-phase hybridization and are rapid and sensitive will have a significant impact on diagnostics and genomics [3]. In this respect, SPE genosensors have several advantages they are safe because they are disposable, they are reproducible, they are inexpensive, and the overall procedure is quite fast. In this respect, electrochemical adsorption (adsorption controlled by a positive potential) is an easy to perform and rapid way of immobilization. The method does not require special reagents or nucleic acid modifications. 

In diagnostic clinical medicine, DNA identification has been applied to investigations of patient tissue specimens obtained during biopsies or autopsies. Because of imaginative adaptations of DNA extraction techniques, the DNA contained in slides and preserved tissue specimens can now be investigated for evidence of infectious or genetic diseases. For example, in situ DNA hybridization is an ultrasensitive technique in which specific DNA probes are applied directly to tissue embedded in paraffin. (Paraffin-embedded tissue specimens are used in microscopic studies. Such slides can be stored... 

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