The invention relates to a novel labeling reactant of formula (I) suitable for
labeling an oligonucleotide
##STR1##
wherein:
R is a temporary protecting group. A is either a phosphorylating moiety or a solid
support tethered to a bridge point Z via a linker arm E. E is a linker
arm between G and Z. G is a bivalent aromatic structure, tethered to two iminodiacetic
acid ester groups N(COOR")2 or G is a structure selected from
a group consisting of
##STR2##
G is a protected functional group. The invention further concerns a method for
direct attachment of a conjugate group to an oligonucleotide structure enabling
the attachment of a desired number of these groups during chain assembly. The method
comprises a Mitsonobu alkylation.
