T4 Gene 32 Protein (1 mg)

A single-stranded DNA binding protein from bacteriophage T4, offered by QIAGEN, that is required for T4 DNA replication, recombination, and repair. The protein stabilizes single-stranded DNA (ssDNA) and unwinds secondary structures, enhancing PCR amplification, RT-PCR and cDNA synthesis efficiency, and DNA sequencing performance—particularly in secondary-structure-rich regions. It binds ssDNA cooperatively and transiently, stimulating T4 DNA Polymerase synthesis on primed single-stranded substrates by 5–10-fold. The protein can also be combined with T4 DNA Polymerase and T4 DNA Ligase for site-specific mutagenesis applications.

Purified from a recombinant E. coli strain that overexpresses the gene 32 protein from bacteriophage T4, the enzyme has a molecular weight of 33,506 Daltons. It is supplied at a concentration of 10 mg/mL in 20 mM Tris-HCl, 100 mM NaCl, 0.5 mM DTT, 1 mM EDTA, and 50% glycerol (pH 8.0 at 25°C), and should be stored at -25°C to -15°C. A glycerol-free formulation is also available on request. The product was developed, manufactured, and sold for in vitro use only and is not suitable for administration to humans or animals.

Quality control testing confirms DNA binding by gel shift assay with a fluorescently labeled oligonucleotide and physical purity greater than 99% by SDS-PAGE with silver stain detection. Contaminating activities are screened at the indicated loadings: single-stranded exonuclease below 1.0% released (100 µg), double-stranded exonuclease below 1.0% released (100 µg), double-stranded endonuclease showing no conversion (100 µg), and E. coli DNA contamination below 10 copies (25 µg). As a starting point for SSB-mediated PCR or NASBA reactions, add 20–320 ng/μL per 50 µL reaction; in standard 50 µL Recombinase Polymerase Amplification (RPA) reactions, a typical working range is 0.2–0.6 µg/µL in the final mixture.