University of Arizona Core Facilities Highlights: Imaging Cores – Optical
At the U of A Imaging Cores – Optical facility, scientists explore worlds invisible to the naked eye, using advanced microscopes to reveal biological structures and processes in remarkable detail.
Doug Cromey and Ved Prakash looking at a high-resolution image of a bumblebee leg.
Taylor Edwards, University of Arizona
One day, researchers bring in a retina. The next, it's a brain, a bumblebee leg or a culture of living cells.
At the University of Arizona's Imaging Cores – Optical facility, or ICOP, scientists routinely explore worlds invisible to the naked eye, using advanced microscopes to reveal biological structures and processes in remarkable detail.
As Doug Cromey, ICOP assistant director, puts it, "We look at everything."
With one location in the Marley Building and another in Life Sciences North, ICOP offers advanced optical microscopy instrumentation and expert support for research, industrial and clinical applications.
Advanced microscopy enables researchers to examine cells, tissue and other objects at magnifications as high as 2,000 x regular human vision to study biological processes in real time and in multiple dimensions, including 3D space, time and wavelengths.
Ved Prakash imaging cell cultures of human fibroblasts.
Taylor Edwards, University of Arizona
Researchers can image samples ranging from whole organisms and tissue sections to single cells and intracellular structures. Available capabilities include brightfield and fluorescence imaging, live-cell imaging, deep tissue imaging, spectral imaging, optical sectioning, three-dimensional reconstruction, and super-resolution microscopy.
Optical microscopes are most commonly associated with transmitted light and epifluorescence. Transmitted light passes completely through the sample, which is usually no more than 4 to10 microns thick – one-tenth the thickness of a human hair. Today’s microscopes can image objects as small as 100 nanometers, or one thousandth the size of a human hair.
Epifluorescence, in contrast, involves the use of a specific wavelength or a narrow range of wavelengths that illuminates one side of a sample. A light-sensitive molecule within the sample absorbs the wavelength and then emits a longer wavelength that is captured by a camera or light-sensitive detector. By using several colors of fluorescent molecules, researchers can learn more about location and relationships within samples.
“We get to see a part of the universe that very few people get to see,” Cromey said. “Every day is different, and that makes work exciting.”
Doug Cromey, Manager, Assistant Director, and Ved Prakash, Core Scientist II, from Imaging Cores - Optical
Taylor Edwards, University of Arizona
The wide variety of samples brought to the optical imaging facility stems from the fact that much of the work done by Cromey and his colleague and fellow scientist, Ved Prakash, involves consultation and training for researchers and students.
“To guide researchers to the right equipment and software, we need to know if their sample is live or fixed, thick or thin, labelled with colored stains, fluorescent dyes, etc.,” Prakash said. “Once we have a good understanding of their goals, we can help train them on the right equipment for their research project.”
Together, Cromey and Prakash have more than 50 years of hands-on experience to offer those seeking to use microscopy in their research. Prakash specializes in developing advanced quantitative bioimaging approaches to new problems. Cromey is a nationally recognized expert in the ethics of scientific digital imaging. The assistance they provide researchers includes hands-on training, imaging challenging samples and maintaining the microscopes to ensure high-quality, reproducible data across disciplines.
(Left) Confocal microscope image of retina (slice) of a Diabetic mouse using a 40x objective. Green = mullerglia, Magenta = astrocytes, Teal = microglia, White = nuceli. (Right) Confocal microscope image of retina (whole mount) of a Parkinson’s mouse using a 40x objective. Green = blood vessels, Magenta = microglia, Teal = astrocytes, White = nuceli.
Courtesy of ICOP, Erika Eggers
Erika Eggers, a physiology professor and associate department head for research who focuses on the retina and diabetic eye disease, has used ICOP and says imaging is now a core part of grants that her lab submits.
“The imaging core and the Zeiss LSM880 confocal microscope has helped expand the research in the Eggers Laboratory in several ways,” Eggers said. “The Eggers lab for many years focused only on neurophysiology of retinal neurons in neurodegenerative diseases. Using the imaging core has enabled us to determine if the neurons we are recording from are lost or have structural changes. Using this imaging has also allowed us to expand into examining vasculature, glia and microglia, which are difficult to study physiologically.”
In the last fiscal year alone, ICOP supported grants totaling $60 million. The facility logged 140 users from 70 labs, representing 28 departments and six colleges, including Agriculture, Life and Environmental Sciences; Engineering; Medicine; Optical Sciences; Pharmacy; and Science.
For more information on resources and services, visit Imaging Cores - Optical.