Oligonucleotides double-strand

Fig. 9. Mutagenesis by a synthetic oligonucleotide of a cloned sequence available in single-stranded form (a) single-stranded M13 template containing uracil (U) residues (b) double-stranded product, uracil residues are not mutagenic (c) strong selection for M13 phages containing mutation of interest (23).

Artificial endonucleases, ie, molecules able to cleave double-stranded DNA at a specific sequence, have also been developed. These endonucleases can be obtained by attaching a chemically reactive group to a sequence-specific oligonucleotide. When the oligonucleotide is bound to its complementary sequence, the activation of the reactive group results in double-stranded DNA cleavage. 

The double-stranded DNA to be amplified is heated in the presence of Taq polymerase, Mg2+ ion. the four deoxynucleotide triphosphate monomers (dNTPs), and a large excess of two short oligonucleotide primers of about 20 bases each. Each primer is complementary to the sequence at the end of one of the target DNA segments. At a temperature of 95 °C, double-stranded DNA denatures, spontaneously breaking apart into two single strands. 

Fluorescence studies and the binding interaction of Quartz/APES/RB with single- and double-stranded oligonucleotides (ssDNA and dsDNA) in Tris-HCl buffer solution of pH 7.4 were carried out. Quartz/APES/RB exhibited emission at 576 nm, whereas Quartz/APES without BB where nonfluorescent, suggesting that RB successfully assembled on the surface of quartz wafers. By comparison with Aem of 5 x 10 5 M RB solution, which was 588 nm, a hypsochromic shift was found. Considering the fluorescence microscopical image of Quartz/APES/RB, it... 

Ying Z, Xiang-Ying S, Bin L (2009) Fluorescent recognition for single- and double-stranded oligonucleotides based on rhodamine B-modified self-assembled bilayers. Chin J Anal Chem 37 665-670... 

The method of PCR allows selective amplification from a complex genome by enzymatic amplification in vitro. The double-stranded genomic DNA template is denatured by heating, and the temperature is then decreased to allow oligonucleotide primers to hybridize (anneal) to their complementary sequences on opposite strands of the template. The... 

Fig. 6.9 Possible topologies of a biomolecular complex constructed from two complementary trisoligonucleotidyles. Each DNA double strand is represented as a single bond, each unpaired oligonucleotide as an unpaired electron. Slightly simplified from Scheffler et al. (1999a, b)...

Figure 2 Double-stranded oligonucleotide photoprobes that simulate modified DNA and intended to cross-link to DNA-binding proteins. (A) Probe modeling interstrand cross-linking by cisplatin Source From Ref. [63], with permission from the American Chemical Society via the Rightslink service (license number 2458870278307 granted June 30, 2010). The benzophenone probe prior to reaction with DNA is shown in the lower part of the panel. (B) Photoaffinity probe for bacterial DNA repair proteins. TT is a simulated thymine dimer intended to be recognized as a site of damage in DNA, and T (two instances) is the diazirine thymine derivative T Source From Ref. [64], with permission from Wiley.

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