US Patent 12065684 Demand synthesis of polynucleotide sequences

The invention provides methods of synthesizing a product DNA molecule having a desired and/or defined sequence. The methods involve annealing at least one long oligonucleotide and at least one short oligonucleotide to at least one anchor strand having a sequence at least partially complementary to the at least one long and at least one short oligonucleotide. The invention also provides methods of synthesizing DNA molecules by assembling oligonucleotide members of a library that contains less than 20,000 members that can be assembled into all possible DNA sequences.