Technology Review – Researchers have created mice that are 500 times more sensitive than usual to TNT. They could provide a cheap, fast way to find buried explosives.
Genetically engineered mice could be created as cheap methods to detect anything that releases molecules into the air. (drug detection, some kinds of cancers and disease)
Scientists are engineering a real-life Mighty Mouse that will scurry through fields sniffing out hidden landmines thanks to olfactory superpowers.
The researchers, at Hunter College of the City University of New York, have genetically engineered the animals to be 500 times better equipped than their normal counterparts to sniff out landmine explosives. They hope that these “hero mice” could warn of buried bombs.
Hidden landmines are a deadly reality in nearly 70 countries globally, and detection and removal are expensive and dangerous. Currently, metal detectors, radar, magnetometers, and sniffer dogs are used to search for them.
A Belgian organization called APOPO already uses giant African pouched rats as a cheaper way to sniff out landmines. The rats are not genetically modified, but their sense of smell is sharp enough to detect TNT. The bomb-sniffing rats are taught to scratch the ground when they detect a hidden mine (fortunately, they are small enough not to set off the explosives). While the furry minesweepers are effective (with two handlers, they can cover a field in one hour that would take two full days for metal detectors), they need nine months of training to become reliable, a process that costs around 6,000 euros per rat.
APOPO has stepped up its war on landmines and aims to spread the use of its unique rat detection and land release methodology through its Mine Action Programs. APOPO continues to develop combined approaches using existing demining technology as well as its innovative Mine Detection Rats (MDRs), leading to greater land release rates. In addition to the current use of these HeroRATs in clearance procedures, the role of rats in technical survey is also being explored, which will have a positive effect on overall efficiency of releasing land.
The genetically engineered mice, however, are so sensitive to TNT that encountering the molecule is likely to change their behavior involuntarily, so they would need little to no training. Charlotte D’Hulst, a molecular neurobiologist at Hunter College who presented her work at a meeting of the Society for Neuroscience, used genetic modification to ensure that the mice have 10,000 to 1,000,000 odor-sensing neurons with a TNT-detecting receptor compared with only 4,000 in a normal animal, “possibly amplifying the detection limit for this odor 500-fold,” she says. Each odor-sensing neuron in a mouse’s nose is spotted with one kind of odor receptor. Usually, each specific receptor is found in one out of every thousand odor-sensing neurons, but about half the scent-detecting neurons in D’Hulst’s mice have the TNT-detecting receptor.