Method for determining intrinsic binding parameters of an analyte to a ligand, a method for selecting an analyte from a group of analytes, the selected ligand or analyte, and sensor

Method for determining intrinsic binding parameters, such as KD, kd and ka, of an analyte to a ligand, such as a drug and a protein, a drug and a receptor, and an antibody and antigen, wherein the maximal binding response RL or Rmax and at least one binding parameter is determined at at least two different ligand surface densities present on a sensor support, and extrapolating the value of the binding parameter to ligand density=0, characterized by RL=O or Rmax=O.

Sensor, preferably for surface plasmon resonance sensor, comprising a sensor support to which is attached at least one ligand, optionally via an anti-ligand, comprising a serial of different ligand surface densities of the ligand preferably having a stepwise or gradual increase of ligand surface densities, on the sensor support at a single surface area and/or at distinct surface areas.