But usually proteins have different values, isoelectric point values, because they have different combinations of these ionizable amino acids. And because this is another property of proteins that is unique to most proteins, we can use this property to basically purify our protein. So if we have a mixture of different types of proteins, we can separate and isolate specific proteins from that mixture by using a method known as the isoelectric focusing method. So the isoelectric focusing technique is basically a method that we can use to purify and mixture proteins by using a specific property of the protein we call the isoelectric points. So let's take a look at the following diagram, which basically describes the setup of isoelectric focusing. So in the setup, we basically create a special type of gel, and we create a PH gradient along that gel.