So, for example, you take some damaged DNA and add all the proteins to it that you think are required to repair it. Then you check if the DNA was repaired. At the moment I'm trying to find out which part of my protein is responsible for what function. So I have mutated it and in about 5 weeks I will have made the protein and can look if it can repair the DNA sample or not.
It can become very technical at times because you must get the conditions right for the proteins to be able to work. For example- the temperature must be right, the pH, the amount of salt in your sample. And you work with sequencers, machines that will purify your samples and the computers controling them.