Astral Scientific is one of Australia’s Leading Supplier for Life Science, Diagnostic and Compounding Pharmacy Supplies.

Call us on: (02) 9540 2055

You have no items in your shopping cart.

CircLigase™ II ssDNA Ligase

ATP-independent, non-catalytic thermostable ligase that catalyses the intramolecular ligation (i.e. circularisation) of ssDNA templates

  • Intramolecular ligation of single-stranded DNA ends containing 5'-phosphates and 3'-hydroxyl groups
  • ATP-independent, non-catalytic enzyme
  • Circularises ssDNA >15 bases long
  • Compatible with high temperature ligation reactions due to thermostability of CircLigase™ II enzyme


  • Production of ssDNA templates for rolling-circle replication or rolling-circle transcription experiments.
  • Production of ssDNA templates for RNA polymerase and RNA polymerase inhibitor assays.

CircLigase™ II ssDNA Ligase* is a thermostable enzyme that catalyses intramolecular ligation (i.e. circularisation) of ssDNA templates having a 5´-phosphate and a 3´-hydroxyl group. In contrast to T4 DNA Ligase and Ampligase® DNA Ligase, which ligate DNA ends that are annealed adjacent to each other on a complementary DNA sequence, CircLigase II ssDNA Ligase ligates ends of ssDNA in the absence of a complementary sequence. The enzyme is therefore useful for making circular ssDNA molecules from linear ssDNA. Circular ssDNA molecules can be used as substrates for rolling-circle replication or rolling-circle transcription.

Linear ssDNA of >15 bases, including cDNA, is circularised by CircLigase II enzyme. Under standard reaction conditions, virtually no linear concatamers or circular concatamers are produced. In addition to its activity on ssDNA, CircLigase II enzyme also has activity in ligating a single-stranded nucleic acid having a 3´-hydroxyl ribonucleotide and a 5´-phosphorylated ribonucleotide or deoxyribonucleotide.

CircLigase II has greater activity and a new Reaction Buffer for improved ligation efficiency.

Figure 1. CircLigase™ II ssDNA Ligase converts linear ssDNA

Unit Definition: One unit of CircLigase II enzyme converts 1 pmol of a linear 5´-phosphorylated CircLigase II Standard 55-mer Oligo into an exonuclease I-resistant circular form in 1 hour at 60°C under standard assay conditions.

Storage Buffer: 50% glycerol containing 50 mM Tris-HCl (pH 7.5), 100 mM NaCl, 0.1 mM EDTA, 1 mM DTT, and 0.1% Triton®X-100.

10X Reaction Buffer: 0.33 M Tris-Acetate (pH 7.5), 0.66 M potassium acetate and 5 mm DTT.

Quality Control: CircLigase II ssDNA Ligase is free of detectable phosphatase, DNA exo- and endonuclease, and RNase activities.

Product Citations

  1. Polidoros, A.N. et al. (2006) BioTechniques 41, 35.
  2. Shroff , H. et al. (2005) Nano Letters 5(7), 1509.
  3. Lin, C. et al. (2006) Angewandte Chemie 118, 7699.
  4. Korlach, J. et al. (2008) Proc. Natl. Acad. Sci. USA 105, 1176.
  5. McArthur, M. and Bibb, M.J. (2008) Proc. Natl. Acad. Sci.USA 105, 1020.
  6. Shroff , H. et al. (2008) Biophysical Journal 94, 2179.
  7. Kuhn, H. and Frank-Kamenetskii, M.D. (2008) Nucleic Acids Res. 36, e40.
  8. Murakami, T. et. al. (2008) Nucleic Acids Res.Doi:10.1093/nar/gkn1014


CircLigase™ II ssDNA Ligase is provided at 100 U/μl.

Contents: CircLigase™ II ssDNA Ligase, CircLigase™ II 10X Reaction Buffer, 50 mM MnCl2, CircLigase™ ssDNA Control Oligo, Betaine, Sterile Water.

List  Grid 

2 Item(s)

Set Descending Direction
per page
Product Code Product Name QTY Price Action
CL9021K CircLigase™ II ssDNA Ligase 1,000 U
CL9025K CircLigase™ II ssDNA Ligase 5,000 U

List  Grid 

2 Item(s)

Set Descending Direction
per page