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The
BioResponse association is developing a wealth of
innovative technical
solutions that combine to form the core technology
of BioResponse for
multiparametric diagnostics, consisting of:
- Antibody
bead assay
- Cell assay
- the
VideoScan measuring system
- AKLIDES®
as the first commercially available system
- Real time
PCR
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Microparticles
- Analysis
of bacterial infection in cell culture model
- Enzyme
assays
The multiple uses of the BioResponse technology in
diagnostics, bio-analytics and pharma screening is
based on the
different fields of application like, e.g. protein
analytics (antigens,
antibodies), DNA analytics or cell analytics with
an abundance of
applications. This wealth demands the initial
focussing of the research
association at the most important and most likely
successfully applied
implementations (infection serology, auto immune
diagnostics, gene
tests and molecular diagnostics for infectious
diseases).
Bead Assay
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The bead
assay (BA) is one of the forms of the
BioResponse technology and allows
analysis of proteins, nucleic acids or other
molecules. The BA is able
to measure different parameters within one
reaction vessel, e.g., one
well of a microtestplate. Microtestplates
consist of 96 reaction
vessels, belong to the routine equipment in a
diagnostics laboratory
and allow for an automatic and parallel
processing of patient samples.
The binding of specific
antibodies from the sample
to one of the different, immobilized
biomolecules can be detected with
a fluorescence-labeled detection antibody. The
biomolecules in question
are bound to fluorescence-encoded
microparticles, so that identifying
the reacting molecules is possible.
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Beadarray
with coded particles
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The amount of work and
materials needed compared to existing immunoassays can
be reduced by
the factor 10. Up to 20 parameters can be examined at
the same time,
this is an innovation in a routine laboratory.
Compared to conventional biochips
with
xy-coordinates, whose parameters are generally printed
in nanoliter
amounts on carrier-materials, the so-called 'nanoliter
liquid handling'
is not applicable. Especially for proteins, this
technology is not
being mastered to produce repeatable results. The
required quality for
screening or confirmatory tests in multiparameter
diagnostics can only
be reached by using the BioResponse technology.
This promising technology was being
developed,
tested and brought to a pre-marketable prototype by
R&D-grants from
the Bundesministerium für Bildung und Forschung (BMBF)
from 2004 to
2007 during the 'Wachstumskern BioResponse' phase.
Through increased sensitivity and
specifity on one
hand, and a drastic reduction of production costs on
the other hand,
the Bead-assay is revolutionary in comparison to other
test systems.
Recently, first products have been introduced into the
market.
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Reaction
scheme
of an antibody test for detecting
anti-nuclear antibodies (ANA)
with the bead assay. Example of an
anti-dsDNA-positive sample. |
Cell
assay
Autoimmune
disease
is the generic term for diseases whose cause
is an
out-of-control reaction of the immune system
against the body's own
tissues. These diseases are known as rheumatic
inflammations and are
characterized by occurrences of autoantibodies
(AAB) that are used as
markers for different kinds of disease
patterns and can also be used as
markers of activity. The qualitative and
semi-quantitative detection of
AAB in human sera is normally carried out with
indirect
immunofluorescence (IFT) on human epithelial
cells (HEp2-strain) that
are being used as a natural antigenic
substrate. IFT-testing on HEp2
cells is a sensitive and proven screening
assay for determining AAB,
and also allows a proposition of certain
underlying antigens and
associated diseases by recognizing patterns of
fluorescence. The
conventional visual analysis of the
immunofluorescence patterns is
disadvantageous because of a high variability
of the expertise of the
analysing person and the degree of
standardization of the lab workflow.
The measuring system
'Aklides' has been developed,
consisting of a robust detection system,
including new solutions in
hard- and software-based analysis of cells and
tissues in combination
with a system design based on existing and
yet-to-be-developed
algorithms to automatically characterize
HEp2-immuno-fluorescence.

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Cell
assay for detection of auto-antibodies on
HEp-2 cells |
Measuring
system Videoscan
The
measuring system
Videoscan was being developed to analyse
microparticles (MP) and cells.
The system excels at highly selective, imaging
multifluorescence
detection.
In order to obtain a number of different colours,
respectively
colour-intensity combinations for the BA, a very
high differentiation
of colours is being used, that no other measuring
system for parallel
detections at present is being able to reach.
Besides being used as a detection systems for
analysing MP, the
Videoscan technology is suitable for in-vivo or
in-situ
characterizations of cells and tissues.
The technological prerequisites for the detection
and automatic
interpretation of cellular patterns of
immunostained cells were being
established in the project Cell-Chip, using the
example of HEp2 cells.
PCR-Array
Real-time-PCR
The LoopTag-probe system, patented by the
partners, allowed the
development of leading pathogen detection kits for
microbiological
diagnostics of infectious diseases. To date, these
tests allow the
differentiation of up to three nucleic acid
targets in patient samples,
the detection of an internal standard as well as
the DNA fragments of
two different causative agents by melting curve
analysis. In doing so,
a sensitivity of up to one pathogenic agent genome
equivalent per
reaction is being achieved.
Microparticles
The microparticles being developed by the PolyAn
GmbH consist of
polymethylmethacrylate (PMMA). For coupling
biomolecules, they can be
equipped with a reactive 3D-surface. For the use
in flowcytometrics,
imaging systems for multiparametric diagnostics
like, e.g., the
BioResponse-system as well as screening purposes,
PolyAn has developed
polymeric microparticles consisting of PMMA, which
are encoded by two
fluorescent dyes.
For every given size there exist up to 20
different bead populations,
which can distinguished by the ratio of both
integrated dyes.
The integration of several fluorophores and the
precise production in
classes of size between 2 - 25 µm with a standard
deviation in size of
less than 2 - 5 % enables the production of a
great number of well
distinguished bead populations for multiplex-uses.
Due to the
3D-functional layer on the particle surface, there
is only slight
amount of aggregation of beads and a high
signal-noise-ratio.
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The
Videoscan process as
fluorescence-spectroscopic detection system
for microparticles and cells
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