So what we are doing with ligation is just sticking the gene of interest into an expression vector.
With this example of ligation I have a vector backbone, which is already been opened by a restriction enzyme and has what we call a sticky end. And then I have my gene of interest, which is a short fragment, which also has sticky ends. And then using a ligation enzyme and mixing these two fragments together the sticky ends will be like stuck together that is what a ligation enzyme will do. So that is incubated in the water bath at 16 degrees for half an hour.