Abstract: The current inventive technology includes systems, methods, and compositions for directly synthesizing sticky ended DNA fragments for subsequent gene assembly. In a preferred embodiment, the inventive technology includes strategies for the direct synthesis of sticky ended DNA with 5? overhangs that have any desired length and base composition, using typical PCR protocols with no additional manipulation. In another embodiment, the inventive technology includes the direct synthesis of sticky ended DNA using chemically modified oligonucleotide primers in a polymerase chain reaction (PCR). In certain embodiments, the inventive technology allows for the generation of larger DNA constructs formed by the sticky-ended assemblies generally described herein compared to traditional synthesis and ligation applications.