Run biomolecular interaction measurements in half the time required for the traditional multi-cycle method without the need for regeneration
In the traditional multi-cycle titration method (figure below, lower panel), analyte samples are injected over the ligand surface at different concentrations. After sample association the analyte is allowed to dissociate from the surface by washing with buffer. Before injecting the next analyte concentration, the remaining bound analyte is removed injecting a suitable regeneration solution. Time-consuming assay optimization may be needed to find a suitable regeneration solution.
KineticTitration (figure, upper panel) removes the need for regeneration and significantly reduces the time required to run a full biomolecular interaction experiment, depending on assay type and number of concentrations up to half the time. In a typical KineticTitration procedure, analyte samples are injected over the surface in a series from low to high concentration without dissociation and regeneration steps between the sample injections. The dissociation rate is measured after the last analyte sample .
When is KineticTitration useful?
KineticTitration is suitable for all biomolecular interaction measurements. It is especially useful when:
- surface is difficult to regenerate
- regeneration is detrimental to the ligand
- less time is available for assay development
Example
The small molecular weight drug Tolcapone (273 Da) binding to human serum albumin (HSA) was measured using KineticTitration. Seven samples of tolcapone were injected from the lowest to the highest concentration in the range of 0.25 – 25 µM. Tolcapone to HSA is a two-state binding process.
KineticTitration is available in 4-channel MP-SPR Navi™ 420A ILVES and 410A KAURIS instruments.
To learn more, see our Application Note #155 on KineticTitration.
DISCLAIMER KineticTitration as used in our instruments (MP-SPR Navi™ 410A KAURIS and 420A ILVES) injects analytes in ascending concentrations directly after each other without buffer flow between injections. This type of analysis should not be confused with “Single Cycle Kinetics”, a type of analysis which is proprietary to Biacore and uses short buffer flow steps between injections. Although “Single Cycle Kinetic”-type experiments can be done in all BioNavis instruments, the analysis of this type of titration is disabled in TraceDrawer. Nevertheless, the Kinetic Titration as here described can be processed by TraceDrawer.
