The Polymerase Step Reaction (PSR) Method for Gene and Library Synthesis.

Current gene synthesis methods often incorporate a PCR-amplifying step in order to yield sufficient final product that is detectable and resolvable from multiple off-products. This amplification step can cause stochastic sampling effects that propagate errors during the synthesis and lower the variability when applied towards the construction of randomized libraries. We present the method for polymerase step reaction (PSR), a simple DNA polymerase-based gene synthesis reaction that assembles DNA oligonucleotides in a unidirectional fashion without the need for a PCR-type amplification (Lee et al., BioTechniques 59:163-166, 2015). The PSR method is simple and efficient with little off-product production, undetected stochastic sampling effects, and maximized variability when used to synthesize phage display libraries.