Bio & Chemical lab
To ensure effective development and evaluation of our sensor systems,
Imego has created a superbly well-equipped laboratory. Projects involving
the development of new immuno-assay platforms require measurements with
standard techniques for reference measurements and evaluations. We have
four different instruments that measure absorbance or fluorescence in
couvettes and microtiter plates, respectively. Furthermore, our stereo
microscope is also of use in these projects.
One of our fluorometers accepts commonly used microtiter plates,
microscope slides, etc. It is possible to measure fluorescence variations
across a well with sufficient lateral resolution (below 2 mm2). Other
more sophisticated equipment allows us to perform time resolved
measurements (time resolution of a few nsec). Our equipment also includes
two polarisers for the incident and reflected/fluorescent light. Thus we
are able to study the effect of polarisation on fluorescence excitation
as well as on the emission of fluorescent light.
Our laboratory also houses a photon correlation spectroscopy (PCS)
instrument for particle measurement below approximately 1 µm. This is
extremely useful in all projects involving particles.
For magnetic particles, our PCS equipment supplements information on the
status of suspensions given by magnetic measurements. We can monitor
particle size distributions, follow the kinetics of aggregation as a
function of change in particle surface coating and suspension chemistry
(pH, salt concentration, etc.)
In projects involving particles our viscosimeter and our instrument for
measuring the isoelectric point of molecules/particles (Z-potential) are
used. Z-potential measurements give an indication of the conditions for
suspension stability as well as enabling us to follow changes in particle
charge as a function of changed chemistry of the nanoparticles. We have
successfully used this equipment to follow the change in charge of
molecularly imprinted nanoparticles upon target absorption
When working with molecularly imprinted polymers we use electrochemical
equipment including a potentiostat/galvanostat and a frequency response
analyzer, as well as other instruments.
In many, if not all, of our biochemical projects, it is important to
measure surface properties and monitor reactions taking place on
surfaces. For these projects we use our “multiskop”. This instrument
makes ellipsometry, surface plasmon resonance (SPR) and contact angle
measurements possible. Our laboratory also has a quartz crystal
microbalance with dissipation monitoring (QCM-D) for measuring surface
reactions.
Both QCM-D and SPR allow us to monitor each step of a chemical reaction
in real time. This is of particular importance when optimising the
chemistry of multistep assays such as sandwich ELISA's. Standard
techniques for measuring for example fluorescence, only give an
evaluation of the performance of the whole assay, while these surface
techniques allow us to monitor the binding of the capturing antibody,
blocking molecules, antigens and detecting antibodies separately
(sequentially). In addition, these techniques do not require specific
preparation of read-out chemistries such as when using fluorescence or
absorbance based detection.