T and B Cell-based Surface Plasmon Resonance (SPR) Assay

Using Surface Plasmon Resonance (SPR) to Quantify the Binding Reaction

Surface Plasmon Resonance (SPR) is a biosensor that uses the optical technique to quantify the binding reaction between biomolecules. SPR occurs when plane-polarized light hits a metal film under total internal reflection conditions, and the SPR signal is decided by the refractive index of the sample buffer on the sensor chip. The principle of the SPR assay is based on the binding of biomolecules to the chip results in variations in the refractive index on the sensor surface.

The SPR technique as a real-time biosensor has become the standard epitope analysis approach. It can quantitatively measure the binding of an epitope to its receptor molecules without the need for labeling antigens or antibodies. With extensive experience in tumor antigen epitope discovery and validation, Creative Biolabs provides T and B Cell-based surface plasmon resonance (SPR) assay for cancer epitope analysis.

Fig.1 Schematic description of ligand bound to the analyte.¹

SPR Assay Service at Creative Biolabs

With cutting-edge equipment and abundant experience in SPR assay development, Creative Biolabs has constructed an SPR-based biosensor platform to analyze crucial epitopes for various cancers, including lung cancer, colon cancer, colorectal cancer, skin melanoma, ovarian cancer, human herpesvirus, HIV, and so on.

Workflow

Introduction of the SPR System

The instrument used in SPR monitoring is automatic and contains:

An optical detection part,
An integrated liquid handling part,
An auto-sampler.

Fig.2 Principal of SPR-based biosensor.³

Multiple Methods for Ligand Immobilization

Specific antigen peptides and variants or overlapping peptides library are synthesized and immobilized on the chip. Ligand immobilization methods are shown below but are not limited to this.

Covalent Conjugation

The reaction between carboxyl and amino is used for covalent immobilization.

Capture Coupling

The interaction between streptavidin and biotin, and Ni2 to his tag is used.
Gold sensor chips are used where no surface chemistry is found.

Data Analysis

The ligand-receptor binding activity is measured in resonance units (RU). For any given interactant, the change in the refractive index on coupling ligands is proportional to the amount of the ligand-receptor complex formed on the sensor surface.
The interaction is recorded and displayed as a sensorgram in real-time, providing binding kinetics information between an epitope and its receptor.

k_on and k_off

The association and dissociation kinetic rate constants, k_on and k_off.
Describe the formation and dissociation of the ligand-receptor complex.

K_D

The equilibrium dissociation constant.
Calculates from k_on/k_off.
Represents the binding affinity of one molecule to another.

The workflow of the CSFE-based assay for T-cell epitope identification. (Terral, et al., 2017) Fig.3 Label-free interaction analysis monitored by surface plasmon resonance.²

Key Features of the Assay

High-sensitive and label-free.
High accuracy and low detection limit.
Real-time monitoring.
Allow multi-site binding experiments.
Measure the binding kinetics.

The SPR assay is a promising technique in the identification of cancer epitopes and biomarkers. Creative Biolabs is devoted to exploring potential cancer epitopes for diagnosis and therapeutics for our clients. Our T and B cell-based assay platform of high efficiency and accuracy can provide customized services to meet your demands. Please contact us for more detailed information.

References

Singh, S. K., Singh, R. Surface Plasmon Resonance, a Novel Technique for Sensing Cancer Biomarker: Folate Receptor and Nanoparticles Interface. Methods Mol Biol. 2022, 2413: 211-228.
Terral, G.; et al. Epitope characterization of anti-JAM-A antibodies using orthogonal mass spectrometry and surface plasmon resonance approaches. MAbs. 2017, 9(8): 1317-1326.
Yanase, Yuhki.; et al. Surface Plasmon Resonance for Cell-Based Clinical Diagnosis. Sensors (Basel, Switzerland). 2014, 14: 4948-59.

For Research Use Only | Not For Clinical Use