So purifying our proteins, as we'll see in just a moment. Now, this can be done because different proteins are composed of different amino acids, and different amino acids contain different hydrophilic and hydrophobic nature. So, because proteins consist of different variation of amino acids, they have different solubilities in water. And that means the salt concentration at which protein salt out will differ from one protein to another. And so if we have two different proteins in, let's say, an Aqueous solution, and those two different proteins have a big variation in their salt concentration at which they salt out, we can basically purify them and separate them by using the salting out method. So let's see exactly what we mean.