[6] In 1954, Swedish investigators Oden and von Hofsten proposed that ninhydrin could be used to develop latent fingerprints.
[7][8] Ninhydrin can be used in Kaiser test to monitor deprotection in solid phase peptide synthesis.
In the analysis of a chemical reaction by thin layer chromatography (TLC), the reagent can also be used (usually 0.2% solution in either n-butanol or in ethanol).
[13] A ninhydrin solution is commonly used by forensic investigators in the analysis of latent fingerprints on porous surfaces such as paper.
The amino acids present in the minute sweat secretions that gather on the finger's unique ridges transfer to surfaces that are touched.
Exposure of the surface to ninhydrin converts the amino acids into visibly colored products and thus reveals the print.
The reaction of ninhydrin with secondary amines gives an iminium salt, which is also coloured, generally being yellow–orange.
[17] A case has been described in which a 41 year old forensic laboratory worker working with Ninhydrin developed rhinitis and respiratory difficulty.