T4 DNA Ligase Highlights

T4 DNA Ligase catalyzes the formation of a phosphodiester bond between the terminal 5′ phosphate and a 3′ hydroxyl group of duplex DNA, RNA, or DNA/RNA hybrids. This enzyme joins blunt and cohesive (sticky) ends, and repairs single-stranded nicks.

  • Activity across a broad range of DNA and RNA inputs enables a variety of applications
  • Supplied with standard or rapid ligation buffers for simple optimization 
  • Reduce material costs with a drop-in solution that delivers equivalent performance at a differentiated price-point
  • Custom formats available, including high concentration
  • Highly stringent enzyme manufacturing ensures quality performance across lots


  • Cloning of restriction digestion and PCR products
  • Joining of linkers or adapters to DNA
  • Nick repair
  • DNA self-circularization


T4 Polynucleotide Kinase

Pairs seamlessly with T4 DNA Ligase for a variety of ligation applications


QC Specifications
Description Specification
Protein Purity Assay ≥ 99%
dsDNA Exonuclease Assay* <1% released
ssDNA Exonuclease Assay* <1% released
DNA contamination Assay (E. coli, mammalian, library)* < 10 copies
Phosphatase Contamination Assay* < 1% released
Endonuclease Contamination Assay* Not detectable

*As assessed using 6,000 U of enzyme input per assay.


Unit definition: One unit is defined as the amount of DNA ligase required to join 50% of 100 ng of DNA fragments with cohesive termini in 20 μL 1X DNA Ligase Buffer following a 30-minute incubation at 23°C

Reaction conditions:
1X Rapid Ligation Buffer*
Incubate at 20-25°C

Storage buffer: 10 mM Tris-HCl, 50 mM KCl, 1 mM DTT, 0.1 mM EDTA, 50% glycerol pH 7.5 @ 25°C
1X Rapid Ligation Buffer: 6% PEG, 66 mM Tris-HCl, 10 mM MgCl₂, 1 mM DTT, 1 mM ATP pH 7.6 @ 25°C

Heat inactivation: 65°C for 10 min

Molecular weight: 55.3 kDa

*Note: Other buffer formulations are also available