SYNTHESIS AND PROPERTIES OF NEW FLUORESCEIN - LABELED OLIGONUCLEOTIDES

2,4-Dinitroaniline is an efficient intramolecular fluorescence-quenche r for fluorescein - labeled oligonucleotides and interacts with the he terocyclic bases on duplex formation. Consequently, intramolecular flu orescence quenching is disturbed in double labeled oligonucleotides of this type, and fluorescein shows strong fluorescence in a duplex form . There is a substential increase of the fluorescence-quantum yield wh en the marker and quencher is attached to a single guanosine residue. Two kinds of doubly labeled oligonucleotides have been synthesized, us ing the NPE/NPEOC strategy.