New Horizons for Ninhydrin: Colorimetric Determination of Gender from Fingerprints

Abstract

In the past century, forensic investigators have universally accepted fingerprinting as a reliable identification method via pictorial comparison. One of the most traditional detection methods uses ninhydrin, a chemical that reacts with amino acids in the fingerprint content to produce the blue-purple color known as Ruhemann's purple. It has recently been demonstrated that the amino acid content in fingerprints can be used to differentiate between male and female fingerprints. Here, we present a modified approach to the traditional ninhydrin method. This new approach for using ninhydrin is combined with an optimized extraction protocol and the concept of determining gender from fingerprints. In doing so, we are able to focus on the biochemical material rather than exclusively the physical image.

Trends in fingerprint analysis

“…A purely chemical-based assay has also been developed for the determination of biological sex from fingerprint samples. This system involves the use of ninhydrin to react with the amino acids present in the extracted fingerprint samples to give a visible colorimetric response [62]. As with the L-AAO system, both mimicked and authentic samples were tested using this system.…”

Promises and Challenges in Continuous Tracking Utilizing Amino Acids in Skin Secretions for Active Multi‐Factor Biometric Authentication for Cybersecurity

“…Presently, such analyses have been reported to distinguish group characteristics: biological sex, ethnicity, etc . for forensics.…”

“…Specifically for sweat, biochemical assays have been developed capable of determining biological sex from samples obtained from fingertips . Some general overviews are available .…”

All Ink-jet Printing Strategy for Extensive Exploration of One Chemical Action with Three Interactive Variations

“…[3][4][5] Ninhydrin colorimetry is a classical method, which is widely utilized in amino acid analysis; this began in the late 1940s. 6,7 This reaction is very complex, and is affected by many factors; however, there has been less research on the factors. In many previous papers, the factors have been analyzed including the pH, concentration and dosage of the reagent, the reaction time and the temperature; more chemical factors and their interactions on the reaction were less studied.…”