Genetically modified mice could help us sniff out explosives and diagnose diseases

That’s the dream of a new project unfolding at Hunter College in New York City, created by neurobiologist Paul Feinstein. Professor Feinstein has spent much of his career exploring the way in which odorant receptors form on the surface of neurons within the olfactory system. Each olfactory neuron has a singular receptor that specializes in a particular smell. Feinstein’s idea is that mice could be made to develop one especially powerful odor receptor: making that particular rodent up to 100x better at detecting specific odors.

“A lot of diseases probably elicit new odors in your body, some of which you might detect and others which you might not,” Professor Feinstein tells Digital Trends. “For example, one odor we know exists is the odor for tuberculosis in sputum samples. APOPO, which is a non-profit organization working in Africa, uses rats to seek out tuberculosis, as well as to search for land mines. What we want to do is to take these rodents and make them pay attention, or be more inclined to recognize, one particular odor.”

To make his mice better at “sniffing out” certain scents, Feinstein and his colleagues developed a DNA string that can can injected into a fertilized mouse egg — thereby making it more likely that the mouse will develop large quantities of specific olfactory neurons.

Right now, Feinstein’s work is still in the research stages. However, in the medium-term he thinks it could be used to create a sort-of “nose on chip” archive. “[We want] to create a library of mouse sensors that each express one human odour receptor, and then to extract the cells from the mice and put them onto a chip so the chip can read out odor signals that will activate those receptors expressed from the cells,” he says.

This work could have a broad range of applications. “If we can make an array of receptors from our mouse sensors on a platform technology like a chip we think we could use that as an odor detection grid — meaning that when a patient starts getting sick we think there’s a code in terms of specific odors which are released by the body,” Feinstein continues. “We think we could diagnose this through non-invasive measures like blood, saliva, urine or sweat. It could be a very powerful diagnostic tool for disease onset or progression.”