Method of obtaining 3'-(2')-amino- or thiolo-modified nucleosides, nucleotides and oligonucleotides coupled with a fluorescent dye

The OH group located in the 3' and/or 2' position of a nucleoside, nucleotide or oligonucleotide is derivatised to an amino or thiol group and subsequently a fluorescent dye is coupled thereto. The resulting 3'- and/or 2'-amino- and thiol-modified nucleosides, nucleotides and oligonucleotides can then be used for the synthesis of items in the presence of a template strand or of oligonucleotides, and for the detection of genetic material. They offer the advantage that the fluorescent label is no longer attached to the 5' end of the oligonucleotide or to the nucleobase and thus does not have to be introduced during the chemical synthesis as in labelling techniques hitherto disclosed, while the known and conventional methods have the disadvantage that only some polymerases can be employed for the synthesis, the acceptance of the triphosphates by the polymerases falls and, in addition, a large substrate excess is necessary.