MIT researchers use sodium polyacrylate, a compound used in diapers, to enlarge brain samples

Researchers at the Massachusetts Institute of Technology (MIT) have come up with an inexpensive technique for enlarging brain samples and studying them more closely. This new technique makes use of commonly available chemicals to help experts increase the size of tissue samples effortlessly and thus provide high resolution images. Called ‘Expansion Microscopy,’ the technique makes use of the same technology that makes the diapers extremely absorbent.

Getting newer, more powerful microscopes might seem to be the most common-sensical retort when confronted with the problem of getting images with better resolutions, but it can also be the most expensive one, which is why researchers at the MIT were looking for ways of enhancing the image resolution from their older, laboratory microscopes.

This search led them on to a substance called sodium polyacrylate which is also packed into babies’ diapers. Making use of this highly absorbent substance, the researchers have been able to make specimens grow bigger, doing away with the need of getting more powerful and expensive microscopes.

To make this method work, the experts painted parts of the biological sample with a fluorescent dye. They then soaked it in a chemical similar to the one used to make the diapers absorbent. The sample did expand, carrying the dye with it. While the expansion destroyed the original molecules, the dye left behind cast a detailed replica of the sample—except that it was five times larger than the original.

“Instead of acquiring a new microscope to take images with nanoscale resolution, you can take the images on a regular microscope,” explains MIT researcher Ed Boyden. He goes on to say, “You physically make the sample bigger, rather than trying to magnify the rays of light that are emitted by the sample.”

Boyden continues, “Unfortunately, in biology that’s right were things get interesting,” adding that protein complexes, molecules which move payloads between and through individual cells, and a host of other cellular processes are all occurring simultaneously in nanoscale.

The new method has been explained in detail in the Journal Science.