Detectives use ninhydrin to reveal fingerprints left at crime scenes. With the Amino Acid Fingerprints: Ninhydrin Demonstration—ChemTopic™ Lab Activity, demonstrate how ninhydrin reacts with amino acids in the natural oils on our skin to produce a purple product and how the color intensity is used as quantitative test for the amount of amino acids in a sample. Available as part of the Biochemistry: The Molecules of Life—ChemTopic™ Labs digital collection. Click the Price link for digital collection pricing.