T4 DNA Ligase (Rapid) (240000 U)

QIAGEN's rapid, high-concentration T4 DNA Ligase is a recombinant protein (55,292 Daltons) produced by an E. coli strain carrying the cloned bacteriophage T4 DNA ligase gene. The ATP-dependent enzyme catalyzes the formation of a phosphodiester bond between the terminal 5' phosphate and the 3' hydroxyl group of duplex DNA or RNA, efficiently joining blunt and cohesive ends and repairing single-stranded nicks in duplex DNA, RNA or DNA:RNA hybrids. It cannot join single-stranded nucleic acids.

The enzyme is formulated at 600,000 U/mL in 10 mM Tris-HCl, 50 mM KCl, 1 mM DTT, 0.1 mM EDTA and 50% glycerol (pH 7.5 at 25°C) and is supplied with a 5x Rapid Ligation Buffer containing 330 mM Tris-HCl, 50 mM MgCl2, 5 mM DTT, 5 mM ATP and 30% PEG 6000 (pH 7.6 at 25°C). Both the enzyme and buffer are stored at –25°C to –15°C.

Designed for fast ligation and improved blunt-end efficiency, the formulation ligates sticky-end DNA in 10 minutes at 25°C and blunt-end DNA in 10–30 minutes, using a 1:3 vector-to-insert ratio at 25°C for best results. Quality control testing shows >99% purity, a specific activity of 300,000 U/mg, less than 1% release in single-stranded and double-stranded exonuclease assays, no conversion in double-stranded endonuclease assays, and less than 10 copies of E. coli DNA contamination. The enzyme enables efficient blunt and cohesive-end ligation and is optimized for cloning, NGS library prep and DNA repair.