Methods for assembling dna molecules

A composition comprising:

• a DNA polymerase, dNTPs, and a plurality of oligonucleotides formed into couplets, wherein each couplet comprises an internal sequence that comprises a portion of the desired nucleic acid sequence;
• wherein when the plurality of couplets is arranged in order, adjacent to each other and according to their internal sequences they comprise at least a portion of a desired nucleic acid sequence, and each couplet further comprises a 3′ or a 5′ primer binding sequence, and each couplet contains a sequence that overlaps and is complementary to a portion of a sequence from an adjacent couplet;
• and
• wherein the desired nucleic acid sequence has a 3′ end and a 5′ end, and the couplets that comprise the 3′ and 5′ ends of the desired sequence further comprise a universal 3′ flanking sequence and a universal 5′ flanking sequence, respectively.