Team:Rutgers

De novo DNA Synthesis is extremely important to the world of Synthetic Biology, but the low efficiency of today's DNA Synthesis technology limits us.

We can only synthesize about 150 bases at a time, so new genes have to be stitched together from smaller strands, which adds a lot to the time and cost required. This needs to change.

We currently use organic (anhydrous) solvents and reactive amidites to synthesize all custom DNA sequences, whether for antibody/enzyme engineering, multi-gene pathway building, or even genome construction. The process looks something like this:

This is one cycle in the process of DNA Synthesis. A solution of blocked nucleotides (whichever A, C, G, or T comes next in the sequence) is added to a group of immobilized DNA strands, and a single nucleotide is incorporated at the end of each strand. The trouble with this highly unnatural method is that each of the chemicals depicted (trichloroacetic acid, 2-benzylthiotetrazole, acetonitrile) causes some harm to the chemical structure of DNA, and this will limit the yield in a way that gets exponentially worse when building longer and longer pieces of DNA.

The process pictured above typically causes enough side-reactions to chemically "break" 1.5% of the existing DNA strands, in each and every cycle (leaving 98.5% of them intact and with correct sequence). This concept is called coupling efficiency, and it's the reason we can only synthesize up to 130-150 bases at a time (or even 200 bases if you're willing to pay a whole lot extra).

We believe that cost follows efficiency -- by eliminating side-reactions in DNA Synthesis, the process could be vastly simplified (cutting capital costs) and less material could be used (cutting operational costs). One way to get huge gains in efficiency for any DNA-related process (see Sequencing, for example) is to utilize If we begin using enzymes that have evolved alongside nucleic acids for billions of years. With DNA Synthesis, this would mean switching from perhaps some cost barriers could be broken.but it may be prudent to begin investigating more natural, aqueous environments for synthesis using enzymes evolved alongside nucleic acids for billions of years.

but it may be prudent to begin investigating more natural, aqueous environments (that are chemically less harmful to the DNA during synthesis) for synthesis using enzymes evolved alongside nucleic acids for billions of years.