快猫短视频

Straining to see the details? 快猫短视频s struggling to make out tiny features of samples under the microscope could opt for expensive, higher-resolution equipment 鈥� or they could just inflate the sample itself to more than four times its original size.

While optical microscopes are suitable for looking at 鈥渓arge鈥� samples, like collections of cells, electron and new super-resolution microscopes allow scientists to see details at the nanoscale. 鈥淏ut these are complex, and difficult to do in 3D,鈥� says at the Massachusetts Institute of Technology.

Boyden and his colleagues 鈥� who are interested in looking at the connections between brain cells 鈥� wondered if they could make the process easier by making their samples bigger. 鈥淚t started off almost as a joke,鈥� says Boyden. But when the team came across a series of decades-old investigations into the uses of smart gels 鈥� polymers that can change their properties 鈥� they wondered if it might be a possibility after all.

The team turned to a polymer found in babies鈥� nappies, which swells on contact with water. When a cell鈥檚 membranes are partially opened using a detergent, the building blocks of the polymer are able to seep into every compartment of the cell. Once this happens, the group trigger a reaction that causes the building blocks to join up, forming the polymer. By adding water, the team are able to make the polymer, and the cell, swell to around four and a half times its original size in three dimensions 鈥� a 100-fold increase in volume.

Having a swell time

The increased size of the sample allows researchers to see more detail using standard optical microscopes. The team can use a microscope that would normally be unable to spot details smaller than 300 nanometres to see details just 70 nanometre big. And because the cells are filled with water, they also become transparent, making it even easier to see what is going on inside them.

A puffed-up sample (right) can be seen in higher resolution than an ordinary sample (left) with a standard microscope (Image: Fei Chen, Paul Tillberg, Ed Boyden at MIT)

Boyden鈥檚 team hope to use to visualise tiny proteins on brain cells, which play important roles in the way neurons connect to and communicate with each other. 鈥淚t could reveal which proteins are there and what they are doing, and whether the connection is strong, weak, slow or fast,鈥� he says. Eventually, this could help researchers create a map of brain connections.

The team hopes the technique will be picked up by other researchers, because the materials involved are already relatively cheap and easy to access.

Enough to make your head swell: some puffed-up mouse hippocampus (Image: Fei Chen, Paul Tillberg, Ed Boyden at MIT)

Chris Edwards, manager of the University of Michigan鈥檚 Microscopy and Image Analysis Laboratory, is impressed. 鈥淪uper-resolution imaging is at the forefront of what drives us microscopists, but the hardware and software currently available to meet those ends is rather expensive,鈥� he says. He believes expansion microscopy could enable high resolution imaging on a budget. 鈥淚t sure looks promising.鈥�

Journal reference: Science, DOI: