Ligation

Linear vector DNA 5-10 µl (50-400 ng)
Insert DNA use a 1:1 up to a 3:1 molar ratio of insert DNA termini to vector DNA
10X ligation buffer for T4 DNA Ligase 2 µl
50% PEG 4000 solution (for blunt ends only) 2 µl
Water, nuclease-free to 20 µl
T4 DNA Ligase 0.2-0.4 µl (1-2 u) for sticky ends; 1 µl (5 u) for blunt ends

Incubate the mixture for 1 hour at 22°C.
Use the mixture for transformation.