FAQ: Do thermostable DNA ligases (such as Taq DNA Ligase, 9°N DNA Ligase, and HiFi Taq DNA Ligase) ligate sticky ends?

While these thermostable ligases can join sticky ends with extensive overlap, like the 12 bp cohesive ends of the genome of bacteriophage Lambda, typical 4 bp overhangs generated by Type II restriction enzymes are not good substrates and will not be ligated. Thermostable DNA ligases are not recommended for use in traditional cloning workflows.