Now, in every step of this process, we basically carry out some type of protein essay for that specific type of protein or enzyme that we actually want to study. And whenever we have whenever we get the highest value for that protein activity, that's the fraction that we actually want to use. That's what the source of protein is that we're going to use. So once we obtain the source of a mixture of proteins and inside that mixture protein, we have that protein that we want to study that will act as a source. And once we have the source, we now can use a variety of different types of specific purification processes. So proteins can be generally proteins can be generally separated based on four important different types of properties.