Patent ID: 8394948

Claim:
A reagent having the following structure: wherein: R 1 =dimethoxytrityl (DMT), monomethoxytrityl (MMT), or other hydroxyl protecting group stable to oligonucleotide synthesis conditions; R 2 =phosphoramidityl wherein R 3 and R 4 are independently selected from the group consisting of C 1-10 branched alkyl, C 1-12 alkyl, and cyclic hydrocarbyls; and R 5 is a phosphite-protecting group X 1 =—CO—CH 2 CH 2 or —CO—CH 2 , X 2 =—NH—, —S—, or —O—; R 6 =a reporter substituent moiety selected from the group consisting of biotinyl, carboxyfluoresceinyl, propargyl, and a hapten-derived substituent moiety; or a suitable protecting group for X 2 .