Patent ID: 7824924

Claim:
A method for determining kinetic constants for a molecular interaction between a first binding partner L and a second binding partner A forming a complex LA, wherein the first binding partner L (ligand) is immobilized on a sensor surface of a biosensor, the sensor surface is contacted with a solution containing the second binding partner A (analyte), and binding of the second binding partner A to the immobilized binding partner L on the sensor surface is detected over time providing response data, the method comprising: raising or lowering several times an analyte concentration c ti (A) of the second binding partner A in a stepwise fashion and before an equilibrium interaction state for the respective analyte concentration c ti (A) has been reached, and without any regeneration of the sensor surface between each raising or lowering of the analyte concentration; and for each stepwise raising of the analyte concentration, comparing an initial rate of association between the ligand and the analyte to the associated response data, to ascertain association related kinetic constants of the interaction, for each stepwise lowering of the analyte concentration, comparing an initial rate of disassociation between the ligand and the analyte to the associated response data, to ascertain dissociation related kinetic constants of the interaction.