ABSTRACT
OBJECTIVE: The system of Strep-Tactin and StrepII tag-SSB proteins binding (ST-SSB) was established to isolate the purified single-stranded DNA in a single step with low cost and high efficiency. RESULTS: We demonstrate that in the presence of large amounts of dsDNA, the ssDNA binding specificity of Escherichia coli (E. coli) single stranded DNA binding (EcSSB) protein was stronger than gene-5-protein (g5p). ST-SSB system relies on the affinity between Strep-Tactin, StrepII tag-SSB protein and ssDNA in binding buffer. Here, we successfully isolated the purified ssDNA from mixed DNA (ds- and ss-DNA form) samples and asymmetric polymerase chain reaction (aPCR) products. This system can purify ssDNA in a single tube within 1 h, and the recovery efficiency of purified ssDNA was around 60%. CONCLUSIONS: The ST-SSB system has obvious advantages of high efficiency and one-step purification to recycle any ssDNA.
