So now that we know the types of amino acids involved, we must determine what the quantity of each one is in our polypeptide. And the way that we're going to do that is use a special type of molecule known as ninhydran. So here we have our five beakers that we basically separated in step two. So in beaker one, we basically have arginine. In beaker two, we have glycine. In beaker three, we have aspartate.