Electron microscopy revealed a world that exists at scales smaller than the wavelength of light. Advancements in this field have allowed scientists to visualize ever more objects and processes, but actually seeing living cells in 3D and within a liquid environment has been impossible.
Now, a team of researchers from Penn State University, Virginia Tech, and a company called Protochips have developed a system that allows for an electron microscope to be used to volumetrically visualize living cells and biological systems that exist in a liquid.
“With this technology that we developed in collaboration with Protochips, scientists could analyze host-pathogen interactions, see a virus being introduced into a cell and watch molecular mechanisms take place in real time,” said Deborah Kelly, professor of biomedical engineering at Penn State and the lead researcher of the study appearing in Nano Letters. “The work represents the world’s first nanoscale CT scan in a liquid environment.”
Using the new system, the team was able to see how a virus and the bacteria that it infects interact within their typical environment. The initial study has already provided some new insights into the workings of the bacteriophage virus, which may potentially lead to new techniques for attacking antibiotic-resistant bacterial strains.
Previously, liquid-cell electron microscopy only allowed for 2D imaging, but the new approach creates imaging slices that are brought together and rendered using a computer. “We use a copper grid that is coated with a carbon layer and cover that with a silicon nitride chip,” added lead author William Dearnaley. “There is a window in the chip and we pipette the liquid sample in between the two layers.”
Thanks to its universal design, the new device works with just about any electron microscope and can be adapted to image a variety of targets. The researchers hope that they will soon be able to see how drug molecules enter and attack cancer cells, potentially using this knowledge to quickly design new drugs.
Study in Nano Letters: Liquid-Cell Electron Tomography of Biological Systems
Via: Penn State