Inspiralis has been supplying T4 DNA ligase for many years. We can supply it in the smaller quantities below or in larger or more concentrated quantities (for example for DNA-tagged chemical library construction).
T4 DNA ligase catalyses the formation of a phosphodiester bond between the terminal 5′ phosphate and a 3′ hydroxyl groups of duplex DNA or RNA. It can ligate cohesive ends of DNA or oligonucleotides, as well as RNA and RNA-DNA hybrids and is particularly efficient at sealing nicks in duplex DNA. It can also ligate blunt-ended DNA but cannot ligate single-stranded nucleic acids. It requires ATP as a cofactor.
T4 DNA ligase is supplied at either 2,000U/ul or 13,000U/ul along with 10X buffer. 1U is a cohesive end joining unit (CELU). 650 CELUs is approximately 1 Weiss unit so 2000 CELUs/ul is equivalent to ~3 Weiss units/ul (TDL1, TDL2) or 20 Weiss units/ul (TDL3C)