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  • DNA Ligase Products

    Learn how DNA cloning/assembly and DNA Ligases from NEB are a natural fit

    With over 40 years of experience in the development and production of enzymes for molecular biology, NEB offers the most extensive selection of high-quality and performance-optimized DNA ligases and master mixes to streamline your cloning experiments.

    A few of our more popular standalone ligases and ligase kits available are:

    1. DNA Ligation

      Ligation, the process of joining DNA fragments with a DNA ligase, proceeds in three steps. Learn more about ligation with our quick animation.

    2. Are some ligations more difficult than others?

      Ligation of blunt ends and single-base overhangs require optimized reaction conditions.

    3. Why do I need to add PEG to my DNA ligation?

      Polyethylene glycol (PEG) is an important reagent in ligation reactions, find out why.

    4. How do I choose the best DNA Ligase?

      NEB continues to develop and produce the most extensive commercially available selection of high-quality, and performance-optimized DNA ligases and ligase master mixes for your ligation needs.

    5. What are the best conditions for DNA ligation?

      Find out how the downstream application dictates the best reaction conditions for ligation.

    6. What molar ratios should I use for DNA Ligation?

      The optimal reactant ratio is contingent upon the downstream application.

    For added convenience and accuracy in your ligation reaction setup, try our new DNA Ligase Master Mixes. These pre-mixed, ready-to-use formulations include a proprietary ligation reaction enhancement agent for improved performance.

    For your convenience, master mixes are available for every end type:

    • For sticky ends, try our Instant Sticky-end Ligase Master Mix (NEB #M0370)
    • For blunt or single-base overhang ends, try our Blunt/TA Ligase Master Mix (NEB #M0367)

    For the full list of DNA Ligases and Ligase Master Mixes offered by NEB, as well as suggested applications, visit the DNA Ligase Selection Chart.

    For information about properties of DNA and RNA Ligaes, visit the Properties of DNA and RNA Ligases Chart.

    For additional help, visit our Ligase Troubleshooting Guide.

    For details on NEB's quality controls for DNA ligases, visit our Ligase Quality page.

    NEBcloner is a guide for selecting appropriate products and viewing protocols for steps in the cloning workflow. To help select the right ligase, choose "ligation" on the tool to start.

    Blunt/TA Ligase Master Mix Outperforms the Competition

    Duplicate ligation reactions of blunt or T/A vector/insert pairs were set upaccording to the master mix vendors' suggestions. Equal amounts of ligated DNA were used to transform NEB 10-beta Competent E. coli (NEB #C3019) and triplicate plating was performed. Transformation results were averaged and graphed as a percentage of the highest performing reaction, T/A ligation using the Blunt/TA Ligase Master Mix.

    Instant Sticky-end Ligase Master Mix Offers Robust Ligation with No Incubation Step

    Reactions containing 20 ng of pUC19 digested with SacI/SphI, and a 3-foldmolar excess of a 1.6 kb fragment from a different plasmid with compatible ends were set up using the Instant Sticky-end Ligase Master Mix. Without any additional incubation time, 2 µl were immediately withdrawn and used to transform a 50 µl aliquot of NEB 10-beta Competent E. coli (NEB #C3019). A 50 µl aliquot of the 1 ml outgrowth was plated onto a selective plate and incubated overnight at 37°C. Results show that several hundred colonies wereproduced.

    ElectroLigase reactions are complete in 60 minutes or less

    Ligation reactions containing equal amounts (20 ng vector and 3-fold molar excess of insert) of blunt (A) or T/A (B)
    vector/insert pairs were set up using ElectroLigase and incubated for the times shown. After heat inactivation of the
    ligase, 2 μl of each reaction were withdrawn and directly used to transform NEB 10-beta Electrocompetent E. coli
    (NEB #C3020). 50 μl aliquots of the outgrowth (diluted, in some cases) was plated onto selective plates and incubated
    overnight at 37°C. Colonies were counted, adjusted for plating dilution, and graphed.

    Electroligase® is a registered trademark of New England Biolabs.
    Quick Ligation™ is a trademark of New England Biolabs
    SilverXpress™is a trademark of Life Technologies, Inc.

    Reported Activities and Applications for T4 Ligases

    Relative Efficiency of T4 Ligases on Nicked Substrates