The next question is, what is the concentration? How many of these amino acids are found in each one of these solutions? So what we do is we take each one of these solutions. 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.