Bli Assay
Bli Assay - Related Videos
07:18
Application of Biolayer Interferometry (BLI) for Studying Protein-Protein Interactions in Transcription
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Cited by 21 •
2019
Interactions of transcription factors (TFs) with the RNA polymerase are usually studied using pulldown assays. We apply a Biolayer Interferometry (BLI) technology to characterize the interaction of GrgA with the chlamydial RNA polymerase. Compared to pulldown assays, BLI detects real-time association and dissociation, offers higher sensitivity, and is highly quantitative.
08:12
The TUNEL Assay
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2023
One of the hallmarks of apoptosis is the nuclear DNA fragmentation by nucleases. These enzymes are activated by caspases, the family of proteins that execute the cell death program. TUNEL assay is a method that takes advantage of this feature to detect apoptotic cells. In this assay, an enzyme called terminal deoxynucleotidyl transferase catalyzes the addition of dUTP nucleotides to the free 3’ ends of fragmented DNA. By using dUTPs that are labeled with chemical tags that can produce...
09:12
Aortic Ring Assay
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Cited by 42 •
2009
Angiogenesis, the sprouting of blood vessels from pre-existing vasculature, is associated with both natural and pathological processes. Here we demonstrate an aortic ring assay that allows angiogenic potentiators and inhibitors to be directly added to aortic rings in culture. Sprouting and neovessel outgrowth can be determined by inspecting the aortic rings over a period of 6-12 days.
10:00
Assaying DNA Damage in Hippocampal Neurons Using the Comet Assay
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Cited by 21 •
2012
The comet assay is an efficient way of detecting single- and double-strand breaks, including alkali-labile sites and DNA-DNA/DNA-protein cross-links on the DNA in all cells including hippocampal neurons. The method takes advantage of the differential migration of DNA in an electric field due to differences in amount of DNA damage.
11:12
Assay Development for High Content Quantification of Sod1 Mutant Protein Aggregate Formation in Living Cells
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Cited by 2 •
2017
We describe a method to quantify the aggregation of misfolded proteins. Our protocol details lentiviral induced stable cell line generation, automated confocal imaging, and image analysis of protein aggregates. As an illustrative application, we studied the effect of small molecules in promoting SOD1 aggregation in a time- and dose-dependent manner.
FAQs
The signal changes because binding alters the thickness of the biological layer at the sensor surface. Reflected light from this surface produces an interference pattern, and the interaction-induced thickness change shifts the measured wavelength. Thus, the optical response follows molecular association or dissociation without requiring a label on the interacting species.
Association and dissociation provide complementary kinetic information. Association records analyte binding to the immobilized partner, whereas dissociation records its departure from the sensor surface. Together, these phases support calculation of association and dissociation rates, which can then be used with the binding response to characterize interaction affinity.
The immobilized binding partner establishes the surface that captures the analyte during measurement. Its presence gives the assay a defined reference point for observing changes in the biological layer as interaction proceeds. The choice of which interaction component is immobilized therefore determines how the sensor presents the molecular binding event.
Real-time monitoring shows when the analyte associates with the immobilized partner and when it dissociates from the sensor surface. This temporal record preserves the behavior of the interaction rather than reducing it to a single endpoint. In biochemical characterization, that distinction helps connect observed binding with kinetic rates and affinity.
A basic BLI assay workflow begins with a biosensor carrying an immobilized binding partner. The sensor is then used to observe an analyte as it associates with and dissociates from that surface. The resulting wavelength shift is monitored in real time, producing a binding response that supports biochemical interaction analysis.
Applications include protein-protein, protein-small-molecule, and antibody-antigen interactions, as well as other biomolecular binding events. This breadth makes the assay useful when biochemical studies need to compare how different molecular partners interact. The same optical readout can support characterization of binding behavior across these interaction classes.
The wavelength shift provides a measurable readout of the interaction as the biological layer changes. Along with the observed association and dissociation behavior, that signal supports calculation of concentration as well as kinetic rates and affinity. Consequently, a BLI assay can contribute both interaction characterization and quantitative biochemical analysis.