Analysis of binding affinity and kinetics
An optical biosensor is a device that detects chemical reactions where the sensing compound – an antibody, enzyme or nucleic acids – is of biological origin. This biosensing compound interacts with the sample (the analyte).
In an optical biosensor, the interaction results in a change between the incoming and outgoing light source. This optical change is detected by a detector.
Optical biosensors are powerful analytical instruments to measure biomolecular interactions in real-time, typically label-free. Binding affinity and kinetics can be measured with high sensitivity.
Image: The schematics of a GCI optical biosensor
Many optical biosensors incorporate microfluidics, meaning that there is an alternating flow of buffer and sample in the system. In an experiment, one of the interactants is immobilized to the sensor surface (the ligand), and the other is free in a solution that’s passed over the sensor surface (the analyte).
An optical biosensor with microfluidics is extremely sensitive and can measure biophysical interactions without being limited by the diffusion of the compounds involved.
The main alternative to microfluidics is labeling the components to get an output that can be detected. These labeled technologies utilize labeled isotopes, fluorescence labeling, and radiolabeling which tends to modify the physicochemical or binding properties, making accurate interaction analysis difficult. Moreover, labeling might alter the ligand structure and/or function, which could affect the experimental results.
Label-free optical biosensors avoid this problem, and because they measure interactions in real time, they also capture accurate kinetic data throughout the binding event, not just at a single endpoint. Techniques such as ELISA, by contrast, only provide an endpoint measurement: binding affinity, without kinetics.
Optical biosensors can provide real-time binding affinity and kinetics. Analysts can directly measure the real-time interaction between molecules, including each stage of association, equilibrium, and dissociation, and this provides deeper insight into both the affinity and kinetics of the interaction. From drug discovery to research, binding kinetics is relevant for many applications, including:
Next-gen bioanalysis platform
Built on market-leading grating-coupled interferometry (GCI) technology from Creoptix, a Malvern Panalytical brand, WAVEsystem unlocks biophysical analysis breakthroughs across a wide range of samples, from small molecules to membrane proteins.
Powered by our next-generation no-clog microfluidic cartridge, the KYMAchip®, the WAVEsystem enables more accurate binding measurements and greater confidence in determining kinetic parameters, with:
Information-rich binding kinetics data you can trust.
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