Your fingerprint can reveal whether you're male or female

Researchers from the University at Albany (UAlbany) are taking crime scene investigation to a new level with the discovery that our fingerprints can be used to identify whether the print belongs to a male or a female.

Writing in the journal Analytical Chemistry, the researchers explained that fingerprint identification over the past 100 years or so has relied mainly on pictorial comparisons. “Despite developments to software systems in order to increase the probability and speed of identification, there has been limited success in the efforts that have been made to move away from the discipline’s absolute dependence on the existence of a prerecorded matching fingerprint,” they wrote.

The UAlbany research team, led by Assistant Chemistry Professor Jan Halámek, took a different approach, instead looking at the content present in the sweat left by fingerprints — namely, the amino acids. They relied on the fact that amino acid levels in the sweat of females are about twice as high as in males. There’s also a slightly different distribution, due mostly to hormonal differences. They therefore sought to test whether the same was true true for amino acids left behind in fingerprints.

First, Halámek’s team extracted amino acids from a fingerprint by transferring it onto a piece of plastic wrap. A hydrochloric acid solution was placed onto the fingerprint, followed by heating. This process allowed for the water-soluble amino acids to migrate into the acidic solution. From there, the team could easily view amino acid levels, distinguishing sex.

The team first tested their method on ‘mimicked fingerprint samples’, which they found to be 99% accurate in correct sex classification. From there, they set up a real crime scene scenario. Three female volunteers placed their fingerprints on five different surfaces, including a doorknob and a computer screen. Regardless of the surface type, Halámek’s team found it was possible to tell the fingerprint belonged to a woman.

“We were able to focus on the biochemical content in the fingerprint using a biocatalytic assay, coupled with a specially designed extraction protocol, for determining gender rather than focusing solely on the physical image,” the researchers wrote.

According to Halámek, this is only the beginning. He’s currently in the process of developing additional identification methods for other forensically relevant attributes, as well as improving on the current fingerprint concept.

“One of the main goals for this project was to move toward looking at the chemical content within the fingerprint, as opposed to relying on simply the fingerprint image,” Halámek said. “We do not intend to compete with DNA analysis or the databases used for identification. Instead we are aiming at differentiating between demographic groups, and more importantly, we are aiming at making use of fingerprints that are smudged/distorted or that don’t have an existing match.”

Image credit: Paul Miller.

Source