Can you tell a person’s gender through their fingerprint?

Law enforcement officials have long relied upon fingerprints as a tool to capture criminals, but for this identification technique to work, there has to be an existing record of a person’s identity. Without this information, these distinctive markings are of little to no use– until now.

Recently, researchers from the University of Albany have come up with a new method that analyzes the chemical composition of fingerprints to determine if it was left it behind by a man or a woman. This technique, according to Gizmodo and Forensic Magazine, analyzes the amount of amino acid content in DNA left behind in the prints.

As Dr. Jan Halamek, an assistant chemistry professor at the university, and his colleagues wrote in the journal Analytical Chemistry, they analyzed residual sweat in search of subtle variations in amino acid content between men and women. Specifically, they noted,  women typically leave behind twice as many amino acids as men, and there are differences in amino acid distribution as well.

This technique doesn’t serve as a replacement for traditional identity-matching techniques, but Halamek’s team believes that it could be useful in cases where the prints left behind are compromised as a way to at least narrow down potential perpetrators.

Gender identification technique 99 percent accurate

The team transferred a fingerprint onto a piece of plastic wrap to extract the amino acids and placed a solution of hydrochloric acid onto the print before heating it. This allowed water-soluble amino acids to migrate into the acidic solution, after which they looked at the amino acid levels and use the data to determine a person’s gender.

The method was first tested using “mimicked fingerprint samples,” the study authors explained in a statement. It was found to have a 99 percent accuracy rate in determining the sex of the man or woman who left behind the fingerprint. Next, they had three female volunteers place prints on five different surfaces, and the method was used to confirm the sex of those individuals.

“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,” Dr. Halamek said. “We do not intend to compete with DNA analysis or the databases used for identification.”

Rather, he said, he and his colleagues “are aiming at differentiating between demographic groups” and “making use of fingerprints that are smudged/distorted or that don’t have an existing match.” The researchers are currently working to improve on the fingerprint technique, and hope to investigate similar methods involving forensically-relevant attributes.

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