5-Methylthioninhydrin (5-MTN) is a reagent for fingerprints that combines the favorable characteristics of ninhydrin (strong colour) and those of DFO and 1,2-IND (strong fluorescence). 5-MTN-developed fingerprints have a stronger colour than those developed with regular ninhydrin. Therefore, the working solution can have a lower concentration (at 3 g per litre, the strength of the colour is about the same). After treatment with zinc chloride, 5-MTN-developed prints do not become orange, but a more reddish coloured purple. The fluorescence of the fingerprint is stronger than DFO.