We basically add this special molecule known as ninhydrin. And what ninhydrate does is it reacts with that amino acid to form a special type of molecule that is able to absorb a particular frequency or a particular wavelength of light. And for 19 of the 20 amino acids, it basically produces a very, very dark blue color or a very, very dark purple color. So we place them in hydrogen, it reacts with our amino acid, and then we basically heat it and we produce a mixture. Now, once we heat that, we can then take a sample out of that beaker, and we can place it into a special apparatus that essentially collects or determines how much light that solution can absorb. And we do that because after heating the solution of Ninhydrate and the amino acid, we can test the solution for light absorption, because the higher the concentration of that amino acid is inside that solution that contains ninhydrin, the more light our solution actually absorbs.