Ninhydrin Test
Objective Ninhydrin reaction is chemical reaction to detect existence of amino acids. Base Theory Ninhydrin (triketohydrindene hydrate) is an oxidating agent which leads to the oxidative deamination of alpha-amino groups. It is very important for the detection and the quantitative analysis of amino acids. Ninhydrin also reacts with primary amines however the formation of carbon dioxide is quite diagnostic for amino acids. When reacting with free amines from the amino acid, blue or purple color is produced. Most of the amino acids are hydrolyzed and reacted with ninhydrin except proline. When ninhydrin reacts with amino acids, the reaction also releases CO 2 . A ninhydrin solution is commonly used by forensic investigators in the analysis of latent fingerprints on porous surfaces such as paper. Amino acid containing fingermarks, formed by minute sweat secretions which gather on the finger’s unique ridges, are treated with the ninhydrin solution which turns t...