Method in a surface plasmon resonance biosensor system
A method for determining instrument-dependent parameters of a surface plasmon resonance, SPR, biosensor system, and using those instrument-dependent parameters to measure the concentration of an analyte is provided herein. Also disclosed are methods of monitoring surface binding interactions of the analyte using the instrument-dependent parameters.
1. A method for measuring the active concentration of an analyte having an unknown concentration using a surface plasmon resonance, SPR, biosensor system, the method comprising the steps of:
a) measuring an active concentration of a known analyte using the SPR biosensor system according to a first method, the SPR biosensor including a chip to which the known analyte can bind, wherein said measuring an active concentration of the known analyte comprises determining the active concentration of the known analyte using an instrument-dependent constant of the SPR biosensor system, wherein the instrument dependent constant includes the width, the height and the length of a flow cell of the SPR biosensor and the known analyte has a known molecular weight, known diffusion constant, known refractive index increment and a known concentration at the time of measuring;
b) comparing the known concentration of the known analyte with the active concentration measured in step a) to determine an instrument error
c) adjusting the instrument-dependent constant of the SPR biosensor system used in the first method by the instrument error obtained in step b) to obtain an adjusted instrument-dependent constant of the SPR biosensor system; and
d) measuring an active concentration of an analyte having an unknown concentration using the SPR biosensor with the adjusted instrument-dependent constant of the SPR biosensor system from step c).
2. The method according to claim 1 , further comprising a step of calculating parameters used to convert SPR biosensor response into mass units from the adjusted instrument-dependent constant of the SPR biosensor system retrieved in step c).
3. The method according to claim 1 , further comprising a step of calculating parameters of the flow cell, and/or parameters of a chip using the adjusted instrument-dependent constant of the SPR biosensor system retrieved in step c).
4. The method according to claim 1 , wherein the first analyte has a known affinity parameter and a known kinetic parameter for a first binding partner.
5. The method according to claim 2 , wherein a mass transport constant is used in the step of calculating said parameters.
6. The method according to claim 1 , wherein step b) comprises measuring active concentration using a calibration-free concentration analysis.
7. The method of claim 1 , wherein the method further comprises monitoring surface binding interactions of the second analyte in the SPR biosensor.
8. The method according to claim 1 , wherein the first analyte is the same as the second analyte.
9. The method according to claim 1 , wherein the measurement is conducted under mass transport limiting conditions.