Kodak Gel Logic 200 Imaging System
 Standing in front
of his recently purchased Kodak Gel Logic 200 Imaging System, Dr. Martin Thompson,
Assistant Professor in the Department of Chemistry, discusses the use of this
fundamental piece of laboratory equipment in high-sensitivity detection of protein,
RNA and DNA samples. "The C2E2 proposal had a lot of support from faculty
in Biology and Foresty, as well as here in the Department of Chemistry,”
says Thompson. "To expand our research in new directions and perform the
kind of cutting-edge research Michigan Tech is known for, you have to have the
right tool for the job. For imaging protein and DNA samples," Thompson
adds, "this is that tool!"
The Century II Campaign Endowed Equipment Fund (C2E2) is an incentive program
designed to provide equipment money to expand the research capabilities here
at Michigan Tech. Contributions from the C2E2 fund and matching funds from the
Department of Chemistry made the purchase of the fluorescence imaging station
possible. “We will use the new instrument in our research in understanding
the mechanism of DNA packaging in cells. This is a formidable hurdle as every
cell has roughly one meter of DNA. Because the proteins involved in DNA packaging
are modular, meaning one part binds DNA, and another part binds neighboring
proteins, we can study packing mechanisms by mutating critical sequences of
the proteins and observing the effects on compactness of the structure. As we
understand the contribution of specific amino acids to the molecular architecture
we also understand the molecular recognition events involved in forming higher
order protein-DNA complexes,” adds Thompson.
 In general, a purification
approach, such as gel electrophoresis, is used for the physical separation of
biomolecules based on their size. Smaller DNA or proteins migrate faster through
the gel matrix than their larger, bulkier counterparts. Washing the gel with
a fluorescent dye and subsequent UV illumination reveals the size (migration
distance proportional to size) and quantity (fluorescent signal is proportional
to amount) of the particular biomolecule. The instrument uses a charge-coupled
device (CCD) to collect light emitted by the fluorescent dyes. Because DNA and
proteins exist in minute quantities a sensitive detection method is required.
The high resolution CCD camera in the Kodak Gel Logic 200 Imaging System is
capable of detecting small fluorescent signals making it an indispensable tool
for multidisciplinary research in chemistry and biology.
The imaging system will be essential in multiple preparatory and experimental
steps in the overall project, including; purification of polymerase chain reaction
(PCR) products, identification of native proteins and experimentation with mutant
proteins. Over the course of a specific research project, graduate and undergraduate
researchers will literally make hundreds of mutant proteins to determine the
factors giving rise to the overall protein-DNA packaging phenomenon. The imaging
system is an indispensable tool in understanding this phenomenon, and being
able to do this type of research here at Tech. Thompson also commented on the
obvious enthusiams from his graduate students, Venkat, Daiva and Renu. "I
suspect that they will never want to leave (lab)."
 The Kodak Gel Logic
200 Imaging System uses a high performance mega-pixel digital CCD camera to
image fluorescent samples under ultraviolet and visible light epi-illumination,
as well as standard transillumination. The result is high background that competes
with signal from the sample. Epi-illumination means the light source is directed
at an angle downwards toward the sample, whereas standard transillumination
emits light from below the sample, directing a large portion of light directly
into the CCD camera. Epi-illumination is oftentimes more sensitive and has less
background by minimizing the amount of scattered background light that gets
back to the detector. This is housed in a black box imaging cabinet with a 1280x960
pixel (57micron/pixel resolution) progressive scan CCD camera mounted at the
top. The CCD camera housing has additional mounts for a 6X lens and light filter
sets. Josh Bailey, a computer savvy undergraduate researcher in Thompson’s
lab has been instrumental in the setup and integration of the device in regular
labwork. “Kodak 1D Image Analysis Software has densitometric function,
meaning it can quantify the amount of fluorescence signal in a given band in
the gel,” exclaims Josh.
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