Synthesis and properties of cross-linked DNA duplexes

AbstractA method has been devised to synthesize DNA duplexes with covalently connected strands. The structure of cross-linked duplexes was confirmed by a reaction with the restriction endonuclease AluI. The thermal stability of the resulting compounds was investigated

Influence of probe structure on unique (regiospecific) cleavage of RNA by RNase H

AbstractChimeric oligo(ribo-deoxyribo)nucleotides with an internucleotide pyrophosphate bond are novel probes for regiospecific hydrolysis of RNA by RNase H. It has been shown that the use of d(TGTGTAT)ppGCCAU leads to unique hydrolysis of the TMV RNA fragment pAAUGGCAUACAC between C10 and A11

Synthetic oligonucleotides: AFM characterisation and electroanalytical studies

One of the most important steps in designing more sensitive and stable DNA based biosensors is the immobilisation procedure of the nucleic acid probes on the transducer surface, while maintaining their conformational flexibility. MAC Mode AFM images in air demonstrated that the oligonucleotide sequences adsorb spontaneously on the electrode surface, showing the existence of pores in the adsorbed layer that reveal big parts of the electrode surface, which enables non-specific adsorption of other molecules on the uncovered areas. The electrostatic immobilisation onto a glassy carbon electrode followed by hybridisation with a complementary sequence and control with a non-complementary sequence was studied using differential pulse voltammetry and electrochemical impedance spectroscopy. Changes in the oxidation currents of guanosine and adenosine were observed after hybridisation events as well as after control experiments. Modification of the double layer capacitance that took place after hybridisation or control experiments showed that non-specific adsorption of complementary or non-complementary sequences occur allowing the formation of a mixed multilayer.http://www.sciencedirect.com/science/article/B6W72-4GP1VK1-1/1/c44e3d2a4c722d5cec59a4d09d0a744