Protein Extraction
Protein Extraction - Related Videos
01:58
Protein Extraction from Neuronal Cells
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2025
This protocol outlines the extraction of proteins from neuronal cancer cells. The cells are washed with a buffer and lysed via enzymatic and mechanical disruption. The extracted protein-rich supernatant is collected after centrifugation.
03:22
SDS-PAGE Based Extraction of Extracellular Vesicles Associated Proteins: A Procedure to Extract Proteins from EVs and Prepare Them for In-Gel Digestion
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2023
In this video, we demonstrate the SDS-PAGE in-gel digestion method for protein extraction from extracellular vesicles or EVs. Once isolated, the obtained protein fragments can be used for proteomic analysis.
03:08
Protein Lysate Extraction: A Technique to Lyse Organoids to Collect Cellular Proteins
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2023
In this video, we demonstrate the extraction of protein lysates from prostate organoids cultured in a basement membrane matrix ring. Analysis of the extracted protein fractions can help study the lineage marker expression in the organoids.
09:13
Optimized Protocol for the Extraction of Proteins from the Human Mitral Valve
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2017
The protein composition of the human mitral valve is still partially unknown, because its analysis is complicated by low cellularity and therefore by low protein biosynthesis. This work provides a protocol to efficiently extract protein for the analysis of the mitral valve proteome.
03:32
Cell-Free Protein Expression Using a Bacterial Crude Cell Extract
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2025
Source: Wiegand, D. J., et al. Cell-free Protein Expression Using the Rapidly Growing Bacterium Vibrio natriegens. J. Vis. Exp. (2019).This video demonstrates the use of a bacterial cell-free protein expression system based on Vibrio natriegens crude lysate to perform coupled in vitro transcription and translation. It highlights the preparation of a master mix with essential components and the step-by-step synthesis of functional proteins from a DNA template.
FAQs
Cell disruption determines whether proteins are released into the extraction solution for subsequent analysis. Mechanical force physically breaks cells, whereas detergents or osmotic methods provide alternative ways to open cellular material. The selected approach therefore forms the first practical control point: incomplete disruption can limit recovery, while effective disruption makes more protein available for later separation and characterization.
The buffered solution helps maintain protein stability after cells are disrupted. This matters because released proteins must remain sufficiently intact for downstream biochemical analysis rather than becoming altered by changing solution conditions. Buffer treatment therefore connects cell disruption with reliable measurement, supporting later examination by gel electrophoresis, immunoblotting, or mass spectrometry.
Protease inhibitors limit protein degradation during sample preparation. Their inclusion helps preserve the proteins present in the original biological sample while the extract is being produced. This protection is especially important when researchers need to compare protein abundance or examine protein properties using downstream biochemical methods, because degradation could change the material being analyzed.
Centrifugation separates the disrupted sample into a soluble-protein fraction and cellular debris. This separation simplifies the extract by removing insoluble material from the portion selected for analysis, while distinguishing soluble components from other parts of the original sample. The resulting fraction can then be used for biochemical characterization or further protein handling.
Once an extract has been prepared, researchers can select an analytical method according to the biological question. Gel electrophoresis, immunoblotting, and mass spectrometry offer different routes for examining the proteins in the sample. Using these methods after extraction allows biochemical investigations to assess protein-related features through complementary analytical approaches.
Protein extraction is useful when experiments require protein-level material from cells, tissues, or other biological samples. Extracts support studies of gene expression, enzyme activity, signaling pathways, and disease mechanisms. They can also provide starting material for protein purification, enabling structural or functional investigation of proteins beyond their original biological context.