Streptavidin Binding
Streptavidin Binding - Related Videos
03:41
Analyzing Influenza Virus Internalization Using a Streptavidin Blocking Assay
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2026
Source: Pohl, M. O. & Stertz, S. Measuring Attachment and Internalization of Influenza A Virus in A549 Cells by Flow Cytometry. J. Vis. Exp. (2015)This video demonstrates the use of a streptavidin blocking assay to distinguish surface-bound from internalized influenza virus in human lung epithelial cells. Comparing fluorescence signals shows that a higher intensity after incubation indicates successful viral internalization.
02:18
The Equilibrium Binding Constant and Binding Strength
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2020
The equilibrium binding constant (Kb) quantifies the strength of a protein-ligand interaction. Kb can be calculated as follows when the reaction is at equilibrium: where P and L are the unbound protein and ligand, respectively, and PL is the protein-ligand complex. As the amount of bound ligand is also related to the rate of ligand binding, experiments can also determine Kb by examining the rates of protein-ligand association (kon) and dissociation (koff) using the following ratio: Thus,...
11:19
Novel RNA-Binding Proteins Isolation by the RaPID Methodology
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2016
RNA-protein interactions lie at the heart of many cellular processes. Here, we describe an in vivo method to isolate specific RNA and identify novel proteins that are associated with it. This could shed new light on how RNAs are regulated in the cell.
05:07
RNA-Protein Pull-Down Assay to Isolate RNA-Binding Proteins via Affinity Extraction
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2025
This video demonstrates an in vitro RNA pull-down assay to identify RNA-binding proteins (RBPs), which interact with the adenylate-uridylate-rich element (ARE) sequences in mRNA. The target RBPs from a cell lysate are mixed with an RNA probe to form RNA-protein complexes. The complexes are isolated via affinity purification utilizing the affinity of the desthiobiotin label of the RNA probe to a streptavidin-labeled magnetic bead.
02:40
Ligand Binding Sites
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2020
Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands. Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
FAQs
The tetrameric form gives streptavidin up to four biotin-binding sites. Each site engages biotin through extensive noncovalent interactions, so one protein complex can provide several points for connecting biotinylated components. This capacity is central to using the interaction as a molecular bridge, whether the goal is capture, detection, or immobilization in a biological experiment.
Extensive noncovalent contacts make the streptavidin-biotin association exceptionally strong and stable under many experimental conditions. That stability helps preserve the connection while a biological experiment uses the complex for purification, imaging, immunoassay, biosensor, or separation purposes. The result is a reliable linkage between a biotinylated target and the experimental component handling it.
Specific recognition allows a biotinylated molecule to connect selectively with streptavidin through a defined molecular interaction. Researchers can therefore attach a protein, nucleic acid, cell, or surface to a capture, detection, or immobilization system. In biology, this selectivity makes the pair a controlled bridge between a target and the tool used to study or handle it.
A basic workflow starts with a biological target that is biotinylated, followed by contact with streptavidin. The resulting association can then be used to capture the target, detect it through a label, or immobilize it on a surface. The selected endpoint depends on whether the experiment seeks purification, imaging, assay readout, or molecular separation.
Affinity purification uses the interaction to capture biotinylated material, while labeled imaging and immunoassays apply it for detection. Biosensors and immobilization formats use the same binding pair to position biological components, and molecular separation uses selective association to handle target molecules. These applications all take advantage of the interaction’s specificity and stability.
The same binding strategy can be applied to biotinylated proteins, nucleic acids, cells, and surfaces. This range allows one molecular interaction to support varied experimental formats, from handling individual biomolecules to studying labeled cells or modifying an experimental interface. Its adaptability helps explain why streptavidin binding appears across many areas of biological research.