Unexpected effect of jellyfish protein on fingerprint detection revealed

Scientists have developed an unusual spray for criminologists

Forensic spray using jellyfish protein could speed up fingerprint detection. Dyes based on fluorescent proteins are also water-soluble and have low toxicity, so they can replace chemical solvents.

Scientists have developed a forensic spray using a protein found in jellyfish that detects fingerprints in just 10 seconds, The Guardian writes.

Aerosol dye could speed up and improve the efficiency of forensic investigations, scientists say. It is also soluble in water and has low toxicity. Traditional forensic methods use either toxic powders, which can harm DNA evidence, or environmentally harmful petrochemical solvents, the sale of which is increasingly restricted.

The dyes in the spray are based on a fluorescent compound called green fluorescent protein (GFP), which has previously revolutionized scientists’ ability to visualize biological processes in cells and animals. The dyes are biocompatible and do not interfere with subsequent DNA fingerprint analysis.

“This system is safer, more robust and faster than existing technologies and can be used even for week-old fingerprints,” said Professor Tony James, a chemist at the University of Bath and co-author of the study.

The team created two different colored dyes, called LFP yellow and LFP red, that bind to chemicals found in sweat and oils in the skin. This locks the dye molecules in place and they emit a fluorescent glow that can be seen under blue light.

“Having two different colors means the spray can be used on different colored surfaces. We hope to produce more colors in the future,” says Professor James.

The fine spray prevents splashing that can damage prints, is less messy than powder, and applies quickly even to rough surfaces where prints are harder to capture, such as brick.

Fingerprints are still used for better identification than DNA evidence in cases where the suspect is unknown and the technology is fast and cheap compared to DNA profiling. However, governments are increasingly restricting the use of solvents used in fingerprint detection methods, including per- and polyfluoroalkyl substances (PFAS), sometimes known as “forever chemicals.”

The GFP protein is naturally produced in the North American jellyfish Aequorea victoria, sometimes called the crystal jellyfish, and emits a green glow when it absorbs blue light. Scientists aren’t sure what purpose the jellyfish’s fluorescence serves, but one possibility is that it helps ward off predators, The Guardian notes.

The protein is already widely used in biological research because the GFP gene can be used as a harmless glow-in-the-dark tag to track the activity of cells in laboratory dishes or inside living things. Flatworms, tadpoles and zebrafish have been reprogrammed with the GFP gene.

Professor Chusen Huang from Shanghai Normal University in China and the project’s principal investigator emphasizes: “We hope that this technology can really improve the detection of evidence at crime scenes.”

The team is collaborating with companies and hopes to make forensic dyes commercially available. Their research was published in the Journal of the American Chemical Society.