| abstract |
Methods and compositions to label oligonucleotides and analogs directly on a solid-support having the structure n n n where S is a solid-support, A is a cleavable linker, X is a moiety with three or more attachment sites, L is a label, Y is a nucleophile, i.e. O, NH, NR or S, and P 1 is an acid cleavable protecting group are provided. The labelled solid-support is reacted in a cyclical fashion to synthesize a labelled oligonucleotide on a solid-support in the 5′ to 3′ direction, having the structure: n n n Labelled oligonucleotides are also synthesized by reacting: (i) a label reagent bearing functionality consisting of carboxylic acid, sulfonic acid, phosphonic acid, or phosphoric acid, (ii) an oligonucleotide on solid support with nucleophilic functionality, and (iii) a coupling reagent, whereby an ester, amide, thioester, sulfonamide, sulfonate, phosphonate, phosphoramidate, phosphorothioate, or phosphate bond is formed. The labelling reaction may be conducted at label sites including the 5′ terminus, the 3′ terminus, a nucleobase, an internucleotide linkage, a sugar, amino, sulfide, hydroxyl, and carboxyl. |