Scientists from Creative Biolabs have extensive experience in affinity and kinetics measurements of biomolecular interactions. We are capable of satisfying any specific demand from our customer.

Background

Affinity and kinetics measurements of biomolecular interactions is a hot issue that researchers concern in recent decades. To perform this, a wide range of methods can be used, such as micro Kjeldahl determinations for protein, Maxam-Gilbert for nucleic acids, and other specific methods for measuring particular biomolecule.

Both Surface Plasmon Resonance (SPR) and Bio-Layer Interferometry (BLI) technologies use a label-free approach to monitor biomolecular interactions as well as providing informations of kinetics and specificity of binding in real time. The platforms based on SPR and BLI technologies (Biacore, ProteOn and Octet) employs the binding of various concentrations of analyte to the immobilized ligands (Figure 1). Based on Biacore, ProteOn and Octet systems, we can provide pharmaceutical development, quality control of biomolecular interactions

Figure 1. The principle of SPR (left panel) and BLI (right panel) technologies.

For various ligands and analytes interactions, we can provide the in-depth analyses as below:

• Concentration range-Obtain an optimal concentration for the affinity constant assay of analyte.
• Kinectics measurements-Obtain the detailed association rate constant and dissociation rate constant (K_a and K_d).
• Affinity measurements-Determining the affinity constant (K_D) based on the association rate constant and the dissociation rate constant (Figure 2).

Figure 2. The calculation of K_D value.

Both SPR and BLI technologies are simplified and high-throughput assay approaches, which are the most suitable for analyte concentration and affinity measurements.

Affinity Measurement for Various Ligands and Analytes

Creative Biolabs provides custom affinity and kinetics measurements for various ligand and analyte interactions based on label-free and high-throughput SPR and BLI technologies. All the data analysis will be performed and documented. Please feel free to contact us for a detailed quote.

Other optional Antibody Affinity Measurement Services:

• Cell Line Affinity Measurement
• Affinity Measurement Services for Specific Antibodies
• Membrane Protein Affinity Measurement
• Affinity Measurement Services for Bivalent Antigens
• Affinity Measurement Services for Dimers/Polymers
• Affinity Measurement Services for Small Molecules
• Affinity Measurement Services for Cell Lysates
• Biacore System
• ProteOn System
• Octet system

FAQ

1. What is the difference between SPR and BLI technologies in measuring interactions between ligands and analytes?

   SPR Technology: SPR measures the change in the refractive index near the sensor surface when ligands and analytes interact. This change occurs due to the mass of the bound analyte and provides real-time data on the kinetics and affinity of the interaction. SPR is highly sensitive and can be used to analyze interactions in complex mixtures.
   BLI Technology: BLI measures interference patterns created by the binding of analytes to a ligand immobilized on a biosensor tip. Unlike SPR, BLI does not require the flow of sample over the sensor, which can simplify the setup and reduce sample consumption. BLI is particularly useful for measuring interactions involving large molecules or particles.

2. How do SPR and BLI technologies quantify the affinity of ligand-analyte interactions?

   Both SPR and BLI technologies provide quantitative data on the binding affinity between ligands and analytes by calculating the equilibrium dissociation constant (KD). In SPR, this is typically achieved by analyzing the steady state or equilibrium binding response at different concentrations of analyte. In BLI, the KD is determined by measuring the rate of binding and dissociation at various analyte concentrations and fitting these data to a binding model.

3. Can SPR and BLI technologies measure the kinetics of ligand-analyte interactions?

   Both technologies are well-suited to measure the kinetics of interactions. They can separately quantify the association rate constant and the dissociation rate constant. This is done by recording how quickly the analyte binds to and dissociates from the ligand. Analyzing these rates helps in understanding the interaction dynamics, which is crucial for applications like drug discovery where the strength and duration of a drug's binding to its target can influence efficacy and safety.

4. What are the typical applications of SPR and BLI in research and development?

   SPR is extensively used in drug discovery for screening drug candidates, characterizing active compounds, and examining the effects of potential inhibitors. It is also employed in antibody engineering and diagnostics development.
   BLI is frequently utilized for the high-throughput screening of antibodies, small molecule therapeutics, and protein-protein interactions. It is also applied in quality control environments to assess the consistency of biological products.

5. What types of samples can be analyzed using SPR and BLI technologies?

   SPR is versatile in handling a wide range of samples, from small molecules and ions to large proteins and complex biological mixtures such as serum or cell lysates. Its sensitivity and ability to operate under various conditions make it suitable for diverse applications, including those involving crude or unpurified samples.
   BLI is particularly effective for samples that are prone to causing nonspecific binding or are in high-viscosity solutions. It can analyze large proteins, antibodies, viruses, and cells. BLI's ability to handle turbid or opaque samples without significant signal interference is a notable advantage.

6. How do changes in buffer conditions affect measurements in SPR and BLI technologies?

   Both SPR and BLI technologies are sensitive to changes in buffer composition, temperature, and pH, which can affect the binding interactions of ligands and analytes. In SPR, variations in buffer conditions can change the refractive index, thus impacting the measurement accuracy. In BLI, buffer conditions can affect the optical properties of the sample, such as clarity and absorption, which may influence the interference pattern detected. Therefore, it is crucial to maintain consistent buffer conditions throughout experiments to ensure reliable and reproducible results.

7. Can SPR and BLI technologies detect conformational changes in proteins during binding events?

   SPR is capable of detecting conformational changes in proteins as these can alter the mass distribution near the sensor surface, affecting the refractive index. This sensitivity to changes in protein structure makes SPR a valuable tool for studying protein folding, complex formation, and the effects of mutations. While BLI is less directly used to study conformational changes due to its focus on interference patterns rather than mass per se, it can still provide insights when such changes affect the overall binding kinetics and stability of the complex.

Resources

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All listed services and products are For Research Use Only. Do Not use in any diagnostic or therapeutic applications.