Researchers in Switzerland have taken a major step forward in understanding human smell by creating lab-grown cells that can detect odors. The breakthrough, announced by Givaudan, a leading fragrance company, was published in the journal Current Biology.
The human nose contains roughly 400 different olfactory receptors, yet in many cases, the substances that activate them remain unknown. Traditionally, studying these receptors has been challenging because the neurons that house them cannot survive in lab cultures.
The Swiss team overcame this obstacle by inserting regulatory sequences into the genes of these receptors and expressing them in HEK 293 stem cells, a widely used human cell line. This modification allowed the cells to acquire the ability to “smell.”
Researchers tested the approach on the first 20 receptors, identifying ones responsible for detecting scents such as grapefruit, patchouli, wood, and amber—the latter derived from sperm whale intestines, a classic perfume ingredient.
A surprising discovery was that many odors activated only a single receptor, contradicting the widely accepted “combinatorial coding” theory of olfaction, which earned a Nobel Prize in 2004. That theory suggests that multiple receptors recognize different parts of a molecule, combining signals to produce a perception of a unique scent. The new findings indicate that, for certain odors, a single receptor may be sufficient.
While future studies may refine or challenge these results, the method itself is already expected to accelerate olfactory research. It could have significant scientific and commercial implications, particularly for the fragrance industry, which seeks to predict the smell of any blend of raw materials.
With 1,500 to 2,000 new perfumes launched annually, this innovation promises to deepen our understanding of scent and enhance the development of new fragrances.
