News

ELVIS is coming to Portland State
Author: Shaun McGillis, Research & Graduate Studies
Posted: December 11, 2018
Enterobacterias

Rock and roll legend Elvis Presley “left the building” for the last time in 1977. Now, over four decades later, another Elvis is gearing up to make an exit, this time from a building at Portland State, to travel some of the most inhospitable environments on earth and possibly beyond.

ELVIS or the Extreme Life Volumetric Imaging System is a new type of microscope designed to study extremophiles, microorganisms that not only live but thrive in the most hostile environments on earth, and as some scientists speculate, on other planets and moons in the solar system. The microscope is being built by Portland State physics professor Jay Nadeau, along with a research team that includes PSU marine microbial ecologist, Anne Thompson, and colleagues Scott Fraser and Thai Truong of the University of Sothern California (USC). The project is supported by a $630,000 grant from the National Science Foundation.

In her lab, Nadeau and research assistant Iulia Hanczarek are huddled around computer monitors watching bacteria scuttle across the screens. Scuttle, but not swarm. The bacteria’s behavior is the topic of discussion. They’re behaving less enthusiastically than they typically do at mealtime. It’s possible, Nadeau reasons, the bacteria are not swarming because they’re getting too much food.

The bacteria’s blasé behavior isn’t the only thing different about the images on the monitors. As Nadeau points out, what we see on the screens is not a recording of an image, as is typical in most types of microscopy. Instead, what we’re observing is a computer rendering of a three-dimensional hologram (yes, like those that have seemingly resurrected such musical icons as Elvis and Tupac Shakur in recent years). Rather than seeing the hologram, however, what we’re looking at is an image produced by a technique called digital holographic microscopy (DHM).

Unlike other branches of microscopy, DHM records light wave information as a digital hologram. Software then converts the image into a two-dimensional display on a screen. The advantage of DHM, Nadeau explains, is that it allows scientists to observe cell-sized objects moving about in a three-dimensional space in real-time. This feature makes DHM particularly useful for studying tiny organism and living cells in their natural environments. There are, however, limitations to DHM. For one, the process of creating an image from a hologram is mathematically complex and can result in poor image quality.

Nadeau, along with Fraser and Truong has devised a way to overcome the limitations of DHM. They plan to combine DHM with Fluorescent Light Field Microscopy (FLFM) in a new microscope: ELVIS.

The instruments on ELVIS will be capable of instantaneously imaging larger sample volumes at a higher resolution than either DHM or FLFM individually. The device will enable researchers studying extremophiles, the origins of life on earth, and the possibility of life elsewhere in the solar system to observe dynamic events, such as bacteria swimming in ways not possible with conventional microscopy.

The research team is building two of the new microscopes. One will serve as a benchtop unit at USC’s Translational Imaging Center. The second was designed as a field instrument to be used by researchers affiliated with PSU’s Center for Live in Extreme Environments to conduct in situ observations in remote or extreme environments such as the open ocean, sea and glacier ice, and hydrothermal vents.

“With this microscope, researchers will be able to study microorganisms in the most hostile environments where they live,” Nadeau said. “Future models could be deployed on missions to Mars to search for signs of microbial life there as well.”

In the long run, Nadeau thinks a tool such as ELVIS can change how biologists approach the study of microorganisms and cells in their natural environments, providing researchers an instrument capable of producing sharper images at a higher capacity than can be achieved today. With this new technology, researchers will gain a better understanding of how life evolved to thrive even under the most extreme environments, be they here on earth or in outer space.

Image: Enterobacteria; Credit: Bet Noire