Green Eggs & Science

Did you know that the eggs of the African Clawed Frog have exemplary ability to express olfactory receptors?

Nobuo Misawaa, Hidefumi Mitsunob, Ryohei Kanzakic, and Shoji Takeuchi did. That’s why the University of Tokyo research team employed the eggs in creating their novel new robotic nose.

According to Physorg.com, the researchers first harvested the immature eggs and injected them with DNA from fruit flies, silk moths and diamond back moths to stimulate production of the insects’ olfactory sensors. The eggs basically performed as a platform for the parts of the insect DNA that had been previously shown to be responsible for detecting gasses, odors, and pheromones. The genetically modified eggs were then placed between a pair of electrodes to form a detector, which measures the current created when the receptors on the egg bind with the odor molecules. The frog egg detectors are far more sensitive and accurate than other biological smell receptors that use the physical vibrations of quartz rods that vibrate when target odor molecules bind to them. These detectors tend to give false positives when other molecules with similar molecular weights to the target molecules bind to them.

Finally, the new frog egg smell sensors were embedded in a robotic mannequin that is designed to shake its head whenever it has a positive response to a scent. The sensor is extremely precise, able to detect moth pheromones with a very high degree of accuracy, especially when compared with other biological smell receptors.

It’s not, of course, really about moth pheromones. Future research using the frog eggs, says team leader Takeuchi, will include robotic detection of such chemicals as carbon dioxide, ketone odor produced by people with diabetes, and aldehydes or other food allergens.