In our discussion on protein purification processes, we discuss four different methods. We begin by discussing the process of salting out, and in salting out, we separate the proteins based on their solubility and salt concentrations. Then we discuss dialysis in which we separate proteins from tiny molecules and ions by using a semipermeable membrane. We moved on to gel filtration chromatography, in which we separate the protein mixture based on their size. And finally, we discussed ion exchange chromatography, in which we separate the proteins based on their net charge. Now we're going to discuss a fifth method by which we can purify our protein mixture.