Immunoprecipitation
Immunoprecipitation - Related Videos
08:08
Co-Immunoprecipitation and Pull-Down Assays
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2023
Co-immunoprecipitation (CoIP) and pull-down assays are closely related methods to identify stable protein-protein interactions. These methods are related to immunoprecipitation, a method for separating a target protein bound to an antibody from unbound proteins. In CoIP, an antibody-bound protein is itself bound to another protein that does not bind with the antibody, this is followed by a separation process that preserves the protein-protein complex. The difference in pull-down assays is that...
08:39
Chromatin Immunoprecipitation
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2023
Histones are proteins that help organize DNA in eukaryotic nuclei by serving as “scaffolds” around which DNA can be wrapped, forming a complex called “chromatin”. These proteins can be modified through the addition of chemical groups, and these changes affect gene expression. Researchers use a technique called chromatin immunoprecipitation (ChIP) to better understand which DNA regions associate with specific histone modifications or other gene regulatory proteins. Antibodies are used to isolate...
21:24
Methylated DNA Immunoprecipitation
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Cited by 43 •
2009
This video demonstrates the protocol for methylated DNA immunoprecipitation (MeDIP). MeDIP is a two day procedure that selectively extracts methylated DNA fragments from a genomic DNA sample using antibodies with specificity for 5 -methylcytosine (anti-5 mC).
09:40
Analysis of the c-KIT Ligand Promoter Using Chromatin Immunoprecipitation
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2017
DNA-protein interactions are essential for multiple biological processes. During the evaluation of cellular functions, the analysis of DNA-protein interactions is indispensable for understanding gene regulation. Chromatin immunoprecipitation (ChIP) is a powerful tool to analyze such interactions in vivo.
01:20
Immunoprecipitation
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2023
Immunoprecipitation, or IP, is a widely used technique that employs protein-antibody interactions to isolate proteins or protein complexes in their native state for studying protein-protein interactions, quaternary structures, or supramolecular complexes. Various modifications of the technique, including chromatin IP, cross-linking IP, and fluorescence IP, are commonly used. Chromatin Immunoprecipitation Chromatin immunoprecipitation, also known as ChIP, is used to study protein-DNA or...
FAQs
Antibody specificity determines which antigen is captured and how much unrelated material accompanies it. An antibody that recognizes the intended target supports a cleaner isolate, whereas recognition of other molecules can complicate interpretation. This selectivity is especially important when the recovered material will be examined for abundance, structure, or associated proteins.
Protein A or protein G beads capture the antibody after it has bound the target antigen. This creates a recoverable solid-phase complex that can be separated from the surrounding biological sample. Their role enables unbound molecules to be removed during washing, leaving the antibody-associated target available for later elution and analysis.
Standard Immunoprecipitation focuses on isolating a selected protein or antigen, while co-immunoprecipitation is used to examine proteins that remain associated with that target. The distinction changes the experimental question: one approach assesses the target itself, whereas the related approach provides evidence about protein-protein interactions within the recovered complex.
The workflow first allows an antibody to recognize the target in a biological sample. Protein A or protein G beads then capture the antibody-antigen complex. Washing removes unbound molecules, and elution releases the retained target from the beads. The recovered material can subsequently undergo Western blotting, mass spectrometry, or another assay.
Western blotting can be used to examine a specific recovered protein, while mass spectrometry can support identification of proteins in the isolate. Other assays may also be appropriate depending on the research question. These downstream analyses allow investigators to evaluate target abundance, characterize recovered material, or investigate associated proteins.
The technique is useful when researchers need to isolate or examine a selected protein from a complex biological sample. In biology, applications include studying signaling pathways, gene regulation, disease mechanisms, and biomarker discovery. When interaction partners are the focus, co-immunoprecipitation extends the approach to investigate protein-protein associations.