Home FAQs What is the difference between the unit definitions of T4 DNA Ligase (NEB #M0202) and Salt-T4 DNA Ligase (NEB #M0467)?

FAQ: What is the difference between the unit definitions of T4 DNA Ligase (NEB #M0202) and Salt-T4 DNA Ligase (NEB #M0467)?

Both T4 DNA Ligase and Salt-T4 DNA Ligase unit definitions are defined as 50% ligation of 0.12 μM HindIII fragments, however, the incubation time/temperature, buffer conditions as well as the method of detection of ligation products differs. The T4 DNA Ligase unit definition is determined after 30 minutes at 16°C, while the Salt-T4 DNA Ligase unit is determined after 10 minutes at 25°C. The T4 DNA Salt-T4 DNA Ligase and T4 DNA Ligase have the same specific activity (1 unit of Salt-T4 DNA Ligase in 1X T4 DNA Ligase Buffer + 100 mM NaCl=1 unit of T4 DNA Ligase in 1X T4 DNA Ligase Buffer).