Studying how live cells respond to extreme conditions shows just how robust life can be, with applications ranging from bioremediation to drug discovery. In looking for a simple way of studying life under the extremes of pressure for example, researchers at Miami University have applied an old idea in new ways.
Capillaries, small diameter tubes (not the blood capillaries in the body), have multiple uses in basic and applied research, but their cylinder-like shapes introduce distortions when used for imaging because the walls are curved.
However, Paul Urayama, assistant professor of physics at Miami, and members of his laboratory found that, despite these distortions, objects smaller than the size of cells can be resolved using a commonly-available deblurring technique called spatial deconvolution. Urayama believes his team's findings provide an alternative to fancier, more expensive pressure-resistant chambers currently in use.
"Investigators interested in pressure tend to shy away from capillaries because they worry about image quality, but we've shown that you don't need to reinvent the wheel," said Urayama. "Conventional image-improvement approaches work when imaging through capillaries. Because capillary chambers are also easy and inexpensive to construct, our results should be of interest to other scientists studying microorganisms under extreme conditions."
Urayama's work with former physics graduate students Thomas Haver and Erica Raber was published in the Journal of Microscopy. Undergraduates Jon Dudley, Michael Salerno and Eric Frey helped design the capillary chamber. Richard Edelmann, director of Miami's Electron Microscopy Facility, and Micheal Eldridge, instrument maker in the physic's department, also participated in the research.
Currently, Urayama uses capillaries as pressure-tolerant chambers to study how extreme environmental conditions affect cellular metabolism. A millimeter-sized glass or quartz capillary is small enough to be compatible with advanced optical microscopy systems, and yet robust enough to withstand pressures found at the bottom of an ocean, which can be up to a thousand atmospheres. Urayama's lab also is researching areas of high-pressure bioscience and biotechnology, including developing state-of-the-art methods for fluorescence-based metabolic ion sensing and microscopy imaging under pressure.