(WashU Magazine) Bringing expansion microscopy to plants

The way we study plant cells is expanding — literally — thanks to new research from Kevin Cox, an assistant professor of biology in Arts & Sciences at Washington University in St. Louis and an assistant member of the Donald Danforth Plant Science Center. In a new study published in The Plant Journal, Cox and his team describe how they have developed ExPOSE (Expansion Microscopy in Plant Protoplast Systems), a technique that brings expansion microscopy to plants.

Traditional imaging methods often come with trade-offs. “We have the low-end microscopes, which are user-friendly but don’t provide much depth and resolution,” Cox explained. “And then the high-end microscopes, where you have really good resolution and data, but it’s a lot to process, and they’re more expensive.”

That’s where expansion microscopy (ExM) comes in. Instead of relying on lenses to zoom in, ExM physically enlarges biological tissues by embedding them in a hydrogel, a water-absorbing polymer that can expand without losing its shape — the same type of material used in products like baby diapers. As the hydrogel swells, so do the cellular structures, making tiny details easier to see under a standard microscope. So, instead of a zoomed-in picture where individual elements may become blurred or distorted, the physical size of the cells increases, like a sponge in water. Better yet, it’s low cost and accessible.

Learn more about Kevin’s research in the full article from WashU Magazine.