Researchers at Cornell University have discovered a way to apply expansion microscopy—which expands cell components to make them more visible—to lipids using click chemistry, which was recently recognized with the 2022 Nobel Prize in Chemistry.

Lipids, or fats, make great walls for cells and organelles because they are water-resistant and dynamic, which is also what makes them traditionally difficult to image. This is especially true when researchers are trying to use expansion microscopy to visualize when different parts of the cell get close to one another.

During expansion microscopy, researchers use chemicals to make a polymer that has charged pieces in it, called side chains. When the sample is placed in water, the side chains absorb it and expand through osmosis to make the sample bigger.

To apply this principle to lipid expansion microscopy, Brittany White-Mathieu, National Institutes of Health Postdoctoral Fellow and first author of the paper, employed metabolic labels that have clickable labels.

“Once the clickable tags are introduced, the cells will happily take these molecules that have these functional groups on them and incorporate them into lipids,” White-Mathieu said. “From there we take a fluorescent reagent we designed that can react with the clickable handles on lipids.”

The reagent contains a polymerizable unit that will get incorporated into the polymer network during the expansion procedure so when the sample is expanded, the lipid is attached directly to the polymer network through the fluorescent compound.

Lipid expansion microscopy can potentially be useful in biomedical research, including to study genetic diseases associated with perturbed lipid metabolism where a lot of fundamental studies of cell metabolism and organization are needed to inform the development of future therapies.

White-Mathieu’s paper was recently published in the Journal of the American Chemical Society.

Information provided by Cornell University.

Laboratory Equipment is powered by Labcompare, the Buyer's Guide for Laboratory Professionals.