Fingerprints may be unique, but without an existing record they can't help identify a person. Now, though, researchers can use chemical analysis of the prints to identify the gender of whoever left them behind.
A team of researchers from the University at Albany has developed a technique which uses the chemical composition of a fingerprint to ascertain gender. It's made possible because of the subtle differences in amino acid concentrations that leech out of human skin: women tend to release twice the levels of amino acids, and in a slightly different distribution to men, too.
A team of researchers led by Jan Halámek decided to see if they could identify those differences even in something as scant as a fingerprint. First, they extracted the amino acids from a fingerprint by transferring it onto a piece of plastic wrap. Then, they washed the print with hydrochloric acid while heating it, encouraging the amino acids to be released. From there, the team analysed the presence of amino acids within the hydrochloric acid.
And boy did it work. The team performed a series of experiments, lifting fingerprints from door knobs, computer screens and other surfaces. Across their tests, they found that they could use the technique to accurately identify the gender of the print's owner 99 per cent of the time. The results are published in Analytical Chemistry.
Obviously actually matching a fingerprint -- or, better, a DNA sample -- is more useful for law enforcement, but the technique could still prove useful. Indeed, Halámek points out that its results could provide vital evidence when fingerprints are smudged or distorted. However it's used, though, expect to see it referenced in a TV detective show soon.
Image by DaveBleasdale under Creative Commons licence