In 1902, the scientist Wood first discovered the phenomenon of SPR in an optical experiment. After a century of theoretical supplementation and technological iteration, it has now become the gold standard in the field of molecular interaction.

To date, SPR has become an indispensable research tool in the field of life sciences.

SPR is a physical optical phenomenon. Put simply, SPR involves different resonance angles on the surface of a metal depending on whether the coupled ligand binds with the analyte. By monitoring changes in the resonance angle, we can infer information about the affinity, binding constants, and kinetics of biomolecular interactions. Therefore, SPR technology has wide applications and significant value in areas such as drug screening, protein-protein interaction research, and antibody-antigen binding.

Principle: When polarized light from a light source is incident into a prism at a certain angle, total reflection occurs at the interface between the prism and the metal. This results in an evanescent wave, an amplitude that decays exponentially in transmission on the surface of the metal, simultaneously inducing surface plasmon waves from the free electrons on the metal surface. When the plasmon wave resonates with the evanescent wave, the intensity of reflected light decreases significantly. The corresponding reflection angle at the lowest reflected light intensity or "dark band" is called the resonance angle. When biomolecules bind to the thin film on the metal surface or interact with already adsorbed molecules, the characteristics of this plasmon wave change, causing a shift in the resonance angle (from A to AB shift)^[10].

This shift can be detected by observing changes in the reflection angle of the incident light. Using the detection system of an SPR instrument, one can measure changes in the resonance angle in real-time and quantitatively, thereby obtaining affinity-related information.

Currently, there are four mainstream methods for detecting intermolecular interactions: Surface Plasmon Resonance (SPR), Glutathione S-Transferase pull-down (GST pull-down), Immunoprecipitation (IP), and Enzyme-Linked Immunosorbent Assay (ELISA). Among them, SPR technology is the preferred detection method for kinetic and affinity analysis in basic life science research, drug development, and medical diagnostic analysis fields. It's also the 'gold standard' for detecting biomolecular interactions.

What are the features of SPR Assay?

• Real-time monitoring, capable of dynamically tracking the entire process of biomolecular interactions;

• Label-free detection, preserving the activity of the molecules^[11];

• Requires very little sample, generally only 100 ug protein is needed for a single surface;

• Convenient and quick detection process with high sensitivity;

• Wide range of applications;

• High-quality analysis data;

• Able to track and monitor the stability of fixed ligands^[12].

The information provided to you by SPR assay:

• Does it bind or not? (Yes or No)
• How specific and selective is the binding? (Specificity)
• What is the strength of binding between the two molecules? (Affinity)
• How fast is the binding and dissociation, and how stable is the complex? (Kinetics)
• What are the temperature and thermodynamic characteristics of molecular binding? (Thermodynamics)
• What is the concentration of the target molecule? (Concentration)

Since Liedberg and others first used SPR technology for antigen-antibody interaction analysis in 1983, SPR technology has been widely used in basic life sciences, pharmaceuticals, food, and environmental science^[5][6]. In recent years, the development of new theoretical and methodological technologies has further expanded the application of SPR technology into emerging fields such as small molecule interaction research, drug screening, clinical diagnosis, and proteomics. Currently, SPR technology is playing an increasingly important role in scientific research.

What services will we provide to you?

MedChemExpress employs the Biacore T200 instrument for affinity analysis, which can be used for the study of interactions such as antigen-antibody, protein-protein, antibody-receptor, VLP protein-antibody, and protein-small molecule compounds. Additionally, MedChemExpress provides customized diversity services for customers.customized services.

Service Advantages

Support for 10,000+ high-quality recombinant protein products.
A professional pre-sales and after-sales technical team.
Advanced equipments.
Real-time, information-rich interaction analysis data

Example 1: Protein-Protein Affinity Determination

Case 1: The affinity between Human NKp30 protein and Human B7-H6 protein was measured using Biacore instrumentation through SPR technology. Using the analysis software of T200 with a 1:1 binding analysis mode for their association and dissociation, the affinity constant was found to be 0.275 μM.

Case 2: The affinity between Human TGFBR1 protein and Mature TGF beta 1 protein was measured using Biacore instrumentation through SPR technology. Using the analysis software of T200 with a 1:1 binding analysis mode for their association and dissociation, the affinity constant was found to be 0.12 μM.

Example 2: Protein-Antibody Affinity Determination

Case 1: The affinity between Human Claudin18.2 VLP protein and Anti-Claudin18.2 Antibody was measured using Biacore instrumentation through SPR technology. Using the analysis software of T200 with a 1:1 binding analysis mode for their association and dissociation, the affinity constant was found to be 1.01 nM

Case 2: The affinity between Human Claudin 6 VLP protein and Anti-Claudin 6 Antibody was measured using Biacore instrumentation through SPR technology. Using the analysis software of T200 with a 1:1 binding analysis mode for their association and dissociation, the affinity constant was found to be 0.19 nM.

MCE is dedicated to providing SPR Assay technology services to scientific research institutions, medical institutions, industrial enterprises, and innovative teams. If you have any questions or needs, please feel free to contact us at any time. Our team of experts will fully support your research projects, helping you to achieve greater breakthroughs and success.

To learn more about SPR Assay technology or to schedule our services, please follow our public account, send an email to [email protected], or directly contact MCE's sales staff. Our professional team will be committed to serving you and customizing SPR Assay services for you!