ExpressLink™ T4 DNA Ligase is a T4 ligase that catalyzes the ligation of blunt or cohesive end DNA fragments in only 5 minutes at room temperature (25°C) and PCR fragments with “A” overhangs in 15 minutes, also at 25°C. T4 ligase catalyzes the formation of phosphodiester bonds between double-stranded DNA strands with 3´ hydroxyl and 5´ phosphate termini in the presence of ATP. ExpressLink™ T4 DNA Ligase formulation is optimized for fast ligase reaction times and more convenient incubation temperature than our other formulations. Single-stranded nucleic acids are not substrates for this enzyme

Product Summary

  • Fast, 5 minute ligation of blunt or cohesive end DNA fragments
  • Fast Ligation of PCR fragments with “A” overhangs in 15 minutes
  • Convenient 25°C reaction temperature eliminates the need for waterbath or temperature block.
  • Ideal for cloning DNA into vectors, recircularization of linear DNA, library construction, TA cloning, and linker ligation.
  • Exonuclease free.

ExpressLink™ T4 DNA Ligase Time Course


Figure 1:  ExpressLink™ T4 DNA Ligase Time Course.
LITMUS 28 vector was gel purified after restriction digest with either EcoRV (blunt) or HindIII (cohesive) and treatment with calf intestinal alkaline phosphatase.  Inserts from a HaeIII digest (blunt) of фX174 DNA and a HindIII digest (cohesive) of λ DNA were ligated into the respective vectors using ExpressLink™ T4 DNA Ligase.  Ligation products were transformed into chemically competent DH10B cells and grown overnight on LB-Amp plates at 37°C.

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Figure 2:  Exonuclease assay. 
A 5’-FAM-labeled 20mer was mixed with 0, 5, 10, or 25 units of various ligase enzymes (ExpressLink™ T4 DNA Ligase, Competitor A, and Competitor B) and incubated at 37°C for 16 hours. The reaction was then mixed with a normalization marker (N), run on a TBE-Urea gel, and imaged.