Issue link: https://resources.nanotempertech.com/i/1050614
7 BioLayer Interferometry (BLI) is a label-free technology for measuring biomolecular interactions. How it works BLI is an optical biosensor-based technique that analyzes the interference pattern of white light reflected from two surfaces: a layer of immobilized protein on the biosensor tip, and an internal reference layer. Any change in the number of molecules bound to the biosensor tip causes a shi in the interference pattern that can be measured in real-time, providing detailed information regarding the kinetics of association and dissociation of the two molecules as well as the affinity constant for the interaction (k on , k off and K d ). Due to the biosensor tip design, the technique is highly amenable to both purified and crude samples as well as high throughput screening experiments. The detection method can also be used to determine the molar concentration of analytes. Strengths Its ease of use and throughput make it an attractive option, especially for labs developing mAb. Kinetic analysis (k on , k off ) and analysis of affinity can also be performed. Measurements are fast as it is a "dip and read" methodology. Weaknesses BLI is a less sensitive and less robust method than SPR, which makes it poorly suited for applications examining small-molecule interaction partners. This, however, does not apply for most mAb applications. As with SPR, a covalent coupling of biomolecules is difficult and faces the same hurdles in terms of immobilization conditions. Moreover, it is hardly possible to achieve identical ligand coatings of multiple biosensor tips, so that regeneration of a tip is still required if concentration series are measured. Especially for high-affinity interactions, the mass-transfer-limitation is an important factor, as well as the limitation in measurement times due to sample evaporation from the plate. Conclusion Although BLI is less sensitive than SPR, it's easier to use. It's a great tool for mAb development workflows. There are options for low, medium and higher throughput sample analysis. BioLayer Interferometry