Bio-Layer Interferometry (BLI) is a relatively new label-free alternative to Surface Plasmon Resonance (SPR) to study the interactions between an immobilized receptor and analytes in solution. Typical capabilities include:
- Quantify the binding of a soluble analyte to an immobilized receptor (KD)
- Quickly screen for high affinity ligands/clones
- Determine IC50 values
- Determine ligand ON and OFF rate constants (kon, koff)
The BLI approach shares some conceptual similarities with SPR, in the sense that the ligand is immobilized on a surface. However, BLI achieves high-throughput by employing a multi-well plate (typically 96 or 384) format, with a row of eight sensors that are dipped into the analyte wells (Figure 1).
- Figure 1. Mechanism of ForteBio Bio-Layer Interferometry ( Ye, R.J. Woods. 2018. Quantifying Weak Glycan-Protein Interactions Using a Biolayer Interferometry Competition Assay: Applications to ECL Lectin and X-31 Influenza Hemagglutinin. Adv. Exp. Med. Biol. (2018) Vol. 1104, Y. Yamaguchi and K. Kato (Eds)).
- A convenient feature of the ForteBio implementation of BLI is the ability to measure up to eight analytes, concentrations, or controls simultaneously. In many cases the analytes may be recovered, helping to conserve valuable reagents.
- BLI is recommended for characterizing interactions that have
· Affinities (KD) between 1 mM to 10 pM, and
· Analyte molecular weights of greater than ~150 Da.
· ForteBio BLI knowledge base https://www.fortebio.com/kb/category.php
- The association phase of the binding is thus dependent primarily on the concentration of the analyte in the wells and to the time the probe is exposed to the analyte (Figure 2).
- To measure analyte dissociation, the probes are automatically raised and transferred to wells containing buffer (Figure 2).
- The times for association and dissociation phases can be adjusted during the experiment, and more complex assays may be programmed.
Figure 2. An example sensorgram of the use of BLI to screen the binding of the lectin wheat germ agglutinin (analyte) to six oligosaccharides (immobilized), simultaneously.
Policy and Costs:
We can perform sample analyses for you or we can train you to do it yourself! Please contact us to discuss your project and define costs: Dr. Ye (Mia) Ji (email@example.com).
For users wishing to analyze their own samples, we provide free mandatory training. Biosensors can be purchased from us, or from ForteBio (https://shop.fortebio.com/dip-and-read-biosensors.html). Only Greiner black flat-bottom 96-well microplates can be used in our instrument (Greiner cat# 655209 https://shop.gbo.com/en/usa/products/bioscience/microplates/96-well-microplates/96-well-polypropylene-microplates/655209.html ).