There are two ways to get a closer look at something very small: build a better microscope or make the object larger.
The problem with the second option – especially if the object of attention is a biological cell, and thus full of liquid – is that enlargement and deformation tend to go hand in hand. The object becomes easier to see, but it also becomes damaged in the process.
Until now. In a paper published in the journal Nature Methods, a team led by Virginie Hamel at the University of Geneva in Switzerland reveal a new approach called Ultrastructure Expansion Microscopy (U-ExM), which permits biological samples to be inflated without the need for prior chemical fixation.
“Cells gradually expand and their components separate from each other while enlarging,” says co-author Davide Gambarotto.
“The architecture of the various elements is preserved and it becomes possible to observe them with a resolution hitherto unattained in optical microscopy.”