As shown in Figure 1, this strategy uses a terminal fluorous tag with conventional solid-phase oligonucleotide synthesis. In the example shown, each iteration of the traditional solid-phase synthesis is followed by an acetate capping step. At the end of the synthesis, a fluorous tag in the form of a fluorous DMT-phosphormaidite is added to the finished oligomer resulting in a mixture of non-fluorous deletion sequences and a fluorous-tagged desired product. Cleavage from the resin, followed by a fluorous solid phase extraction (FSPE) removes all capped deletion sequences from the fluorous tagged full-length sequence which is retained on the fluorous solid phase. On-cartridge detagging then cleaves the fluorous tag providing the desired oligonucleotide.
Fluorous approaches to oligonucleotide chemistry were first demonstrated by Bannwarth and by scientists at Berry and Associates. The latter group achieved unprecedented levels of recovery and purity for oligonucleotides as long as 100 nt in length. These results have been verified by Glen Research.
Berry and Associates has introduced a complete line of reagents for fluorous purification of oligonucleotides. These fluorous tags can either be temporary tags such as the DMT for purification purposes, permanent tags for oligonucleotide immobilization on fluorous surfaces, or tags for oligonucleotide modifications such as quenchers and phosphorylation. Links to individual product pages on the Berry and Associates website are given on the left sidebar.