Abstract: The subject invention concerns novel reagents and methods useful for introducing functional groups and labels at multiple sites of a nucleotide. The reagents are useful, for example, in constructing labeled oligonucleotide hybridization probes for detecting the presence of a target polynucleotide in biological or chemical samples.

Abstract: A trifunctional reagent possessing a primary hydroxyl, a secondary hydroxyl, and a primary amino group. This reagent is useful in solid phase oligonucleotide synthesis for the convenient labeling of the 3'-terminus. The secondary hydroxyl may be an phosphoramidite derivative permitting the attachment to the solid phase support. The reporter molecule may be attached to the trifunctional molecule prior to the completion of the oligonucleotide synthesis or after the oligonucleotide is cleaved from the support. A preferred species of this trifunctional molecule is shown below.