Reduction of metal ions by boranephosphonate DNA.

Oligodeoxyribonucleotides bearing boranephosphonate linkages (bpDNA) were shown to reduce a number of metal ions and form nanoparticles through a novel reaction pathway that leads to phosphate diesters or phosphate triesters in water or alcohols respectively. The synthetic utility of this reaction was further demonstrated through the synthesis of oligodeoxyribonucleotides containing phosphate triester linkages. This new reactivity also makes bpDNA promising for use in construction of DNA templated metallic nanostructures.

Synthesis of high-quality libraries of long (150mer) oligonucleotides by a novel depurination controlled process.

We have achieved the ability to synthesize thousands of unique, long oligonucleotides (150mers) in fmol amounts using parallel synthesis of DNA on microarrays. The sequence accuracy of the oligonucleotides in such large-scale syntheses has been limited by the yields and side reactions of the DNA synthesis process used. While there has been significant demand for libraries of long oligos (150mer and more), the yields in conventional DNA synthesis and the associated side reactions have previously limited the availability of oligonucleotide pools to lengths <100 nt.

Synthesis of mixed sequence borane phosphonate DNA.

A novel solid-phase phosphoramidite-based method has been developed for the synthesis of borane phosphonate DNA. Keys to this new approach are replacement of the common 5'-dimethoxytrityl blocking group with a 5'-silyl ether and the use of new protecting groups on the bases (adenine, N6-dimethoxytrityl; cytosine, N4-trimethoxytrityl; guanine, N2-[9-fluorenylmethoxycarbonyl]; thymine, N3-anisoyl). Because of these developments, it is now possible for the first time to synthesize oligodeoxynucleotides having any combination of the four 2'-deoxynucleosides and both phosphate and borane phosphonate internucleotide linkages (including oligomers having exclusively borane phosphonate linkages).