Agarose Bead Purification
Agarose Bead Purification - Related Videos
13:46
Immunoprecipitation-Based Techniques: Purification of Endogenous Proteins Using Agarose Beads
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2023
Source: Susannah C. Shissler1, Tonya J. Webb1 1 Department of Microbiology and Immunology, University of Maryland, Baltimore, MD 21201 Immunoprecipitation (IP, also known as a 'pull-down' assay) is a widely used technique that has applications in a variety of fields. First conceived in 1984, it was refined in 1988 (1, 2). The fundamental goal of IP is purification and isolation of a specific protein using an antibody against that protein. The word "immuno" refers to the use of an antibody while...
12:04
Isolation and Purification of Drosophila Peripheral Neurons by Magnetic Bead Sorting
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Cited by 25 •
2009
In this video-article we present a method for the isolation and purification of Drosophila peripheral neurons using a fast magnetic bead assisted cell sorting strategy. RNA obtained from the isolated cells can be readily used for downstream applications including microarray analyses.
06:30
Gel Purification
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2023
Gel purification is used to recover DNA fragments after electrophoretic separation. DNA recovery from an agarose gel includes three basic steps: binding, washing and eluting from a silica column. DNA is believed to bind to silica in the presence of high salt via a salt bridge. Following binding, DNA is washed of impurities and eluted under low salt conditions disrupting this interaction. This video goes through a step-by-step, generalized procedure for cutting out a band from the gel, gel...
08:16
Plasmid Purification
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2023
Plasmid purification is a technique used to isolate and purify plasmid DNA from genomic DNA, proteins, ribosomes, and the bacterial cell wall. A plasmid is a small, circular, double-stranded DNA that is used as a carrier of specific DNA molecules. When introduced into a host organism via transformation, a plasmid will be replicated, creating numerous copies of the DNA fragment under study. In this video, a step-by-step generalized procedure is described for how to perform plasmid purification.
11:22
GST-His purification: A Two-step Affinity Purification Protocol Yielding Full-length Purified Proteins
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Cited by 18 •
2013
In the present protocol, we demonstrate a highly efficient and cost-effective small-scale protein purification method, which allows purification of recombinant proteins by uniquely combining a cleavable GST-tag and a small His-tag.
FAQs
Selectivity comes from the ligand attached to the agarose surface. The ligand is chosen to bind the desired protein or biomolecule more specifically than other sample components, allowing the target to remain associated with the beads while unrelated substances stay in solution. This selective interaction is the central mechanism for isolating a target from a complex biological sample.
Porous agarose particles provide a solid support with accessible internal space for ligand-mediated interactions. Their structure allows target molecules to contact the attached ligand while the bead-bound material can later be separated from the surrounding liquid. This combination supports selective capture, physical handling, washing, and recovery within one purification process.
Elution changes the conditions that maintain the interaction between the target and the bead-bound ligand. Adjusting pH or salt concentration can weaken binding, while adding a competing ligand can displace the captured molecule. Choosing among these approaches provides a way to release purified material after contaminants have been removed.
A typical workflow combines sample contact, separation, washing, and elution. The complex sample is allowed to interact with the ligand-bearing beads, after which the beads are separated from unbound material. Washing removes remaining contaminants, and a changed solution condition or competing ligand releases the target for collection and downstream analysis.
Centrifugation and filtration separate the agarose beads from the liquid phase without requiring the target to be removed from the beads immediately. This makes it possible to discard unbound components, introduce wash solutions, and then collect the fraction released during elution. The choice of separation approach depends on how the bead suspension is handled experimentally.
The technique is useful when researchers need cleaner material from a complex biological sample. Applications supported by the method include protein purification, immunoprecipitation, and analysis of molecular interactions. By isolating selected molecules and removing unbound components, it prepares samples for downstream biological experiments that require a more defined molecular composition.