Bathophenanthroline‐ruthenium(II) complexes as non‐radioactive labels for oligonucleotides which can be measured by time‐resolved fluorescence techniques

Abstract

The specific attachment of bathophenanthroline‐ruthenium(II) complexes as non‐radioactive label molecules to synthetically 5′‐NH2‐modified oligonucleotides is described. After excitation by light pulses, the fluorescence of these labels can be measured by a time‐resolved mode woth high sensitivity. No quenching takes place due to coupling of the Ru complexes to the DNA. Ru‐complex‐labelled oligonucleotides still hybridize specifically to complementary DNA sequences, and no quenching is observed in the course of the hybridization process.

Synthesis of oligosaccharides with oligoethylene glycolspacers and their conversion into glycoconjugates usingN,N,N ? ,N ? -tetramethyl(succinimido)u roniu mtetrafluoroborate as coupling reagent

“…have demonstrated the use of TSTU as an efficient reagent for the formation of carboxamides from carboxytic acids. The reagent is compatible with an aqueous solvent system, but activation in N,N-dimethylformamide (DMF) was more efficient [9,10]. To dissolve hydrophilic, unprotected oligosaccharides the use of water as solvent is often a necessity and always an advantage.…”

“…General procedure for the synthesis of the deacylated spacer glycosides [8][9][10][11] The acetylated glycoside (100mg, 0.16-0.19mmol) was dissolved in ethanol (5 ml) and deacetylation was accomplished by addition of 0.25M sodium hydroxide (4 ml) and stirring at room temperature for 1 h. Neutralization with Dowex H + resins, filtration and concentration afforded the desired products 8-11 in quantitative yields. (8) -3,6,9,12-tetraoxatetradecanoic acid (9).…”

“…(8) -3,6,9,12-tetraoxatetradecanoic acid (9). (10) -3,6,9,12-tetraoxatetradecanamide (12) N,N,N',N"-Tetramethyl(succinimido)uronium tetrafluoroborate (TSTU) (59 mg, 0.20 mmol) was added at room temperature to a stirred solution of 9 (51 mg, 0.12 retool) and triethylamine (17.1 gt, 0.12 retool) in 2 ml dioxane:water (4:1 by vot).…”

“…We now report that N,N,N',N".tetramethyl(succinimido)uronium tetrafluoroborate (TSTU), shown to be a good reagent for the formation of carboxamides [9,10], efficiently transforms carboxylic acid spacer oligosaccharide derivatives into active esters and glycoconjugates. * This paper was first published in Glycoconfltgate Journal 10:197-201.…”

Fluorescent Oligonucleotides - Versatile Tools as Probes and Primers for DNA and RNA Analysis

“…29 Also, thermodynamically stable charge-transfer complexes of transition metal ions with high fluorescence emission, large Stokes shift and elongated life times up to 2 µs were coupled to oligonucleotides ( Figure 4). 30,31 Those properties are advantageous since they considerably improve the signal-to-noise ratio and thereby the detection limit.…”