摘要 |
A method is provided for determining binding stoichiometry for the interaction between a first molecule and a second molecule forming a complex between them. Either (i) a solution having a fixed initial active concentration of the first molecule is titrated with solutions of varying active concentrations of the second molecule, and the free active concentrations of the second molecule are measured; or (ii) a solution with fixed initial concentrations of the first molecule and the second molecule is incubated, and the free active concentrations of both molecules are measured. In the first case, the binding stoichiometry can be determined from the initial concentration values of both molecules and the free concentration value(s) of the second molecule at saturation; and in the second case from the initial concentration values of both molecules and the free concentration values of both molecules. Active concentration measurements are typically performed by an interaction analysis sensor, using a calibration-free analytical format at least for the determination of active initial concentrations. |