The speed of ligation is the main difference between the two. The Thermo Scientific Rapid DNA Ligation Kit enables fast sticky-end or blunt-end DNA ligation in only 5 minutes at room temperature. The kit contains T4 DNA ligase and a specially-formulated 5X rapid ligation buffer optimized for fast and efficient DNA ligation. Fast ligation efficiency is equal to that obtained with T4 DNA ligase in a standard 1 hour ligation.