Hybridized nucleic acids

Figure 12.16 Photographs of solutions of (a) polymer 12, (b) 12 + single-stranded DNA, and (c) 12 + double-stranded DNA. (d) Schematic description of the formation of pol)dhio-phene/single-stranded nucleic acid duplex and polythiophene/hybridized nucleic acid triplex forms. Reprinted from Ho et al. (2002). Copyright 2002 Wiley-VCH Verlag GmbH and Co. KGaA.

Bhatt, B, Bums, J, Flannery, D., and McGee, J. O D. (1988) Direct visualization of single-copy genes on banded metaphase chromosomes by nonisotopic in situ hybridization. Nucleic Acids Res 16,3951—3961... 

Peterson AW, Heaton RJ, Georgiadis RM (2001) The effect of surface probe density on DNA hybridization. Nucleic Acids Res 29 5163-5168... 

Li Q, Luan G, Guo Q, Liang I. A new class of homogeneous nucleic add probes based on specific displacement hybridization. Nucleic Acids Res 2002 30 E5. 

There has also been an extensive search for backbone structures other than aminoethyl glycine that may support Watson-Crick base pairing to complementary DNA and RNA. Although many structures have been pursued, little success has been observed. Structures that are based on peptides (i.e., true peptide nucleic acids) have been reported. These derivatives are virtually unable to hybridize nucleic acids but some do display the ability to form homoduplexes [14,15,38-42]. 

A fair comparison should also mention, however, the disadvantages of aptamers DNA and especially RNA are very sensitive to hydrolytic digestion by nucleases, thus requiring highly pure environments for their applications. Several solutions to transform aptamers into nnclease-resistant moieties by the modification of a ribose ring at the 2 -position (Pieken et al., 1991) or by the specific modification of the pyrimidine nncleotide were reported (Heidenreich and Eckstein, 1992 Kusser, 2000), and snch hybrid nucleic acid are anticipated to provide the stabihties requested. 

Unless hybridization to two probes is contemplated (sandwich hybridization), nucleic acids to be analyzed must be labeled for capture or detection. 

Scheme 22.4 Schematic description of the formation polythiophene-single stranded nucleic acid duplex and polythiophene-hybridized nucleic acid triplex...

FIGURE 13.19 (a) Conformations and corresponding UV-Vis absorption spectra of a chromic polythiophene (b) schematic description of the formation polythiophene/single-stranded nucleic acid duplex and polythiophene/hybridized nucleic acid triplex (c) UV-Vis absorption spectrum, and (d) fluorescence spectram of a solution of ((a) polymer (b) polymer-DNA duplex, (c) polymer perfect match triplex, (d) polymer mixture with two mismatches, and (e) polymer mixture with one mismatch). Reprinted with permission from [184]. Copyright 2008 American Chemical Society. 

Staining Applications Nucleic acids cells bacteria ° chromatin genes leukocytes nu-clei micronuclei megakaryocyte microorganisms peptides proteins antibodies sperms Biological Applications Nucleic acid hybridization nucleic acid amplification assay DNA fragment siz-... 

The formation of messenger RNA should also conform to the rule of base pairing. In any case, it can be demonstrated that template RNA is complementary to DNA since one can make hybrid nucleic acids, which are double-stranded molecules consisting of one DNA and one RNA chain (cf. Section 3). 

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