Dual Fingerprint Reagents with Enhanced Sensitivity: 5-Methoxy- and 5-Methylthioninhydrin
“Dual fingerprint reagents” are chemical formulations which produce with latent fingerprints in a single step, impressions that are both colored and fluorescent. Pre-mixed solutions of the two commercially available ninhydrin analogues, 5-methoxyninhydrin (MN) and 5-methylthioninhydrin (MTN) with zinc or cadmium salts, are true dual reagents. They are much more sensitive than the parent dual reagent, ninhydrin/ZnCl2. The main advantage of the new formulations is that they can be used at room temperature, with no need to cool the sample to liquid nitrogen temperature. At 0.05% concentration, which is 10-fold lower than the common ninhydrin working solution, MTN/ZnCl2 is as sensitive as DFO in the fluorescence mode and considerably more sensitive in the color mode. MTN is also slightly cheaper than DFO.
Document Type: Research Article
Affiliations: 1: Casali Institute of Applied Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. 2: Latent Fingerprint Laboratory, Division of Identification and Forensic Science (DIFS), Israel Police, National H.Q., Jerusalem 91906, Israel.
Publication date: March 1, 2008