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Fourier-Transform SPR Analysis using the SPR100 Demonstrates SPR Response in Conducting Metal Oxides
Surface Plasmon Resonance (SPR) analysis is a well established technique in life science research for monitoring molecular interactions such as antibody-antigen recognition and protein-ligand binding. Advances in GWC’s SPR measurement systems are now leading to the increased use of SPR analysis in materials science applications.
Most SPR systems measure events on gold or silver surfaces, with glass as the supporting dielectric needed to elicit the SPR response. SPR measurement on gold surfaces is an extraordinarily versatile technique in life science, as illustrated by the broad range of life science applications proven for GWC's SPRimager®II analysis platform. As a practical matter, until now, the restriction of measurements to gold or silver surfaces limited the application of SPR analysis in materials science.
Theoretically, the SPR response can be elicited from any conducting material. In a landmark paper published in the Journal of Applied Physics, Rhodes et al. used GWC’s patented technique of Fourier-Transform SPR analysis (FT-SPR) to test whether conditions can be found under which a conducting metal oxide (CMO) elicits the SPR response. Using a modified version of the SPR100 instrument, Rhodes et al. showed for the first time that SPR measurements can be made on the CMO indium tin oxide. Moreover, the work suggests that SPR measurement will be generally applicable to CMOs, establishing the utility of FT-SPR analysis for helping to understand the properties of these complex materials. These results are expected to lead to the use of FT-SPR analysis for materials characterization in the semiconductor industry, where CMOs are routinely used in critical components.
The SPR100 system is marketed by Thermo Electron Corp. under license from GWC Technologies. For more information on the SPR100, please contact your
Thermo or GWC Technologies representative or email
Timothy J. Stultz Appointed
to GWC Technologies Board of Directors
GWC Technologies is pleased to announce the appointment of
Timothy J. Stultz, PhD to the Board of Directors. Dr Stultz
is President & CEO of Imago Scientific Instruments, a
rapidly-growing nanotechnology company based in Madison, Wisconsin.
According to GWC Technologies’ President & CEO Tim
Burland, “Tim Stultz has over 20 years of executive
management and strategic development experience in high technology
and capital equipment manufacturing, including positions as
founder and President of Peak Systems, Inc., President &
CEO of ThauMDx, LLC, and VP GM of Veeco Instruments. We are
delighted to have such a capable individual on our team to
help with our business and funding strategies.” Tim
Burland added that among his many accomplishments, Dr Stultz.
has extensive experience in raising capital, both private
and public, as well as success in several mergers and acquisitions.
GWC Technologies develops, manufactures
and markets scientific instruments for researchers in pharmaceutical,
biotechnology and academic organizations worldwide. The company’s
products serve the rapidly growing “proteomics”
market segment, providing detection systems that help researchers
to understand protein function.
For more information, please contact
Tim Burland, President & CEO, GWC Technologies Inc., 608.441.2722.
Use of SpotReady™
ligand arrays to profile cell surface receptors published in
the Journal of Proteome Research
In a collaboration between the laboratory of Lloyd M. Smith
at the University of Wisconsin-Madison and GWC Technologies, Peelen
et al. fabricated ligand arrays on SpotReady™ chips,
using covalent linkage via aldehyde or N-hydroxy succinimidyl
(NHS) ester-modified surfaces. When live, whole cell populations
of BHK21 cells were exposed to the arrays, the cells attached
specifically to the ligands for which they are known to carry
cell surface receptors. Exemplar data show specificity of BHK21
attachment to bFGF (basic fibroblast growth factor) ligands
but not to cytochrome C control probes. The cells also attached,
with intermediate affintiy, to insulin ligands on the array.
These results pave the way for efficient cell receptor profiling
using ligand arrays on SpotReady™ chips and the SPRimager®II
system to monitor binding.
For access to detailed protocols, please contact your
GWC Technologies representative or email
to support project to characterize monoclonal antibodies that
target huntingtin protein
Technologies has agreed to work with the laboratory of Dr.
Richard R Burgess in the Department of Oncology at the University
of Wisconsin-Madison to characterize monoclonal antibodies that
target the huntingtin protein, the abnormal form of which is associated with Huntington’s Disease.
mAbs to be used in this work were developed by Neoclone
Inc., a leading developer and manufacturer of antibodies.
These mAbs will be characterized using GWC’s SPRimager®II
platform. According to Dr. Burgess, “The beauty of the
approach… …is that it is flexible, it does not
require that the mAbs be purified prior to use, and it does
not require the labeling of any mAb or other protein with
radioactivity or fluorescent dyes.” The ability to circumvent
antibody purification stems from GWC’s demonstration
that functional antibody arrays can be made on SpotReady™
chips by direct spotting of ascites fluid. This approach also
serves to preserve valuable reagents since only sub-microliter
volumes of ascites fluid are needed in any one experiment.
The project is made possible through an
Industrial & Economic Development Research Program grant
from the University of Wisconsin-Madison Graduate School to
Dr. Burgess. A successful outcome of the project would provide
a basis for improved diagnostic and theraputic approaches
to Huntington’s disease.
For information on characterizing antibodies
using the SPRimager®II platform and SpotReady™ chips,
please contact your GWC Technologies representative or email
commences drug absorption profiling project with QBI Life Sciences
GWC Technolgies today announced a collaboration with QBI Life
Sciences to develop a drug absorption profiling system. QBI
has been awarded a Phase I SBIR grant to develop methods to
use their PreserveX™ polymeric micelles in drug absorption
modelling studies. GWC Technologies is providing array fabrication
expertise for the project and analysis services using GWC’s label-free SPRimager®II
Development of technologies
for early drug absorption profiling for novel drug candidates
is one of the crucial issues facing modern drug discovery.
Current approaches are low-throughput and suffer from difficulties
with poor reproducibility and poor compatibility with existing
instrumentation. Principal Investigator Dr. Vladimir
Trubetskoy, QBI’s Director of Polymer Chemistry, and GWC's
Chief Scientific officer, Dr Voula Kodoyianni, plan to overcome
these barriers by developing new
methods based on the companies’ available products for
proteomics research. This novel assay will use a mixture of
amphiphilic polymers that can extract membrane proteins and
lipids from natural membranes by formation of stable polymeric
micelle-membrane component complexes (PM-Mem). The resulting
micelles can be effectively immobilized on GWC’s SpotReady™
arrays via polymeric tethers. Each array accommodates multiple
spots with biological membrane components extracted from various
tissues. This technology provides significant benefits over
traditional liposome sensor coatings due to the stability
of PM-Mem. The project deliverable is a system for standardized
profiling of the absorption characteristics of drug candidates.
GWC's PCR-free, label-free,
real-time amplification technology featured in leading review
In the cover story of issue
#12 of Langmuir volume 22, Hye Jin Lee, Alastair W. Wark,
and Robert M. Corn highlight the features of GWC’s AmpliFast™
technology for detection of nucleic acid targets. Invented
in Dr. Corn’s laboratory, the array-based technology
has proven both specific and sensitive for detection of DNA
targets. DNA complementary to RNA probes on the array leads
to specific degradation of the RNA probes when the enzyme
RNase H is added. Loss of RNA probe from the surface is monitored
in real time on GWC’s label-free SPRimager®II system.
Since the target DNA survives the enzymatic reaction, it is
free to hybridize to another RNA probe, leading to further
probe loss and higher signals. Amplification of the signal
in this way is at least 12,000-fold. This surface enzyme reaction
has been thoroughly characterized by Corn and colleagues,
and is now established as a robust, quantitative, real-time
method for nucleic acid detection. The method also forms the
basis of GWC’s proprietary label-free, PCR-free, reverse-transcription-free
now available for cell receptor profiling on ligand arrays using
GWC Technologies today made available detailed experimental
procedures for preparation of protein ligand arrays that can
be used to profile the presence of specific receptors on the
surfaces of live cells. The exemplar data show that BHK21 cells
bind to bFGF (basic fibroblast growth factor) on SpotReady™
protein arrays, but not to cytochrome C controls on the same
array. This specificity of cell binding can be used to profile
multiple receptors on the same cell population by exposing the
cells to SpotReady™ ligand arrays.
access to detailed protocols, please contact your GWC Technologies
representative or email
array platform proves its mettle in direct comparison with vastly
more expensive system
In a paper published in the premier edition of the journal Calcium
Binding Proteins, Subramanian
et al. report an improved method for label-free analysis
of protein-protein interactions. The work was based on a collaboration
between GWC and Arthur Polans' group funded by an Industrial
& Economic Development Research Program grant from the University
of Wisconsin-Madison Graduate School to Dr. Arthur Polans at
the University of Wisconsin, and from GWC Technologies. Subramanian
et al. developed a method for fabrication of protein arrays
on GWC’s SpotReady™ chips. The method uses engineered
proteins tagged with SBP (Streptavidin-Binding Peptide), which
has significant advantages over methods that use GST-tagged
proteins, a popular alternative. In the landmark paper, the
researchers measured the affinity of the interaction between
ALG-2 and Annexin XI, an interaction identified as important
in the development of certain cancers of the eye. As expected,
the measured affinity for the interaction was higher on the
open-platform SPRimager®II, which provides for free access
of analyte to the protein array. Remarkably, the protein array
prepared on GWC’s SpotReady™ chip proved to have
dramatically longer functionality, remaining usable for protein
interaction analysis after six months of storage.
advice on protein array fabrication for the SPRimager®II
platform, please contact your GWC Technologies representative
GWC Technologies array system
featured in Science Magazine product Article
In the Article “Proteomics - Interacting Instruments”,
Mike May and Gary Heebner report on products used in protein
analysis. The article recounts the versatility of GWC’s
SPRimager®II platform and SpotReady™ chips for proteomics
the Science Article.
presents poster detailing proof of principle for application
of AmpliFast™ detection to gene expression analysis
Dr. Christine Angevine, GWC’s Applications Scientist,
presented a poster today in the innovation corridor at the BIO2006
conference in Chicago. The poster detailed how the AmpliFast™
method can be used to monitor mRNA levels in whole cell mRNA
populations without the use of reverse transcription, target
amplification, or fluorescent labelling. Data in the poster
demonstrated femtomolar sensitivity of the method for target
DNA detection and specificity of the method for target mRNAs.
The AmpliFast™ method is based on the published research
of GWC co-founder Robert M. Corn and colleagues (e.g.
Goodrich et al.).
AmpliFast™ sublicensing opportunities please contact
GWC Technologies presents SPRimager®II
array platform at BIO2006 conference in Chicago
Tim Burland, GWC’s President and CEO, today presented
the company’s label-free SPRimager®II array platform
to attendees at the BIO2006 conference in Chicago. The presentation
emphasized the unmatched combination of versatility and affordability
of the platform, and detailed its effectiveness for analysis
of antibody-antigen interaction, cell receptor profiling,
and drug absorption modelling.
protocol now available for preparing monoclonal antibody arrays
direct from ascites fluid for analysis on the SPRimager®II
GWC Technologies today made available detailed experimental
procedures for preparation of monoclonal antibody (mAb) arrays
by direct spotting of unpurified ascites fluid on SpotReady™
chips. Using mAbs raised against RNA polymerase, exemplar data
using mAbs provided by Neoclone Inc. show that measured affinities
are indistinguishable for probes made by direct spotting of
ascites fluid versus direct spotting of purified antibody.
For access to detailed protocols, please
contact your GWC Technologies representative or email
with any questions or comments.