Cell Lysis and Protein Extraction


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Obtaining maximal yields of soluble proteins from cells requires efficient cell lysis. However, overly
harsh lysis conditions can denature or degrade the protein of interest. EMD Millipore has developed
many reagents to enable gentle, efficient cell lysis.

Protease Inhibitor Cocktails and Inhibitor Sets
Ensure the integrity of purified proteins for downstream analysis and accurate characterization by using protease inhibitor cocktails and highly specific protease inhibitors. During protein expression and isolation, endogenous proteases rapidly begin to degrade protein samples, reducing the quality and quantity of protein samples required for characterization and analysis. By using the right combination of protease inhibitors, you can protect your purified protein preparations from the most common proteases including serine proteases, metalloproteases, cysteine proteases, aminopeptidases, and aspartic proteases.

Key Features
Recommended ApplicationProtease Inhibitor CocktailCatalogue No.
General useProtease Inhibitor Cocktail Set I539131
Bacterial cell extracts (except those intended for metal chelation chromatography)Protease Inhibitor Cocktail Set II539132
Mammalian cells and tissue extracts purified using metal chelation chroma¬tography; samples to be analyzed by 2-D gel electrophoresisProtease Inhibitor Cocktail Set III, EDTA-Free539134
Mammalian cells and tissue extracts purified using metal chelation chroma¬tography; samples to be analyzed by 2-D gel electrophoresisProtease Inhibitor Cocktail Set V, EDTA Free539137
Proteins containing His•Tag® sequencesProtease Inhibitor Cocktail Set VII539138
Protein Extraction Reagents
Our BugBuster®, YeastBuster™, and CytoBuster™ Protein Extraction Reagents are innovative combinations of detergents and other ingredients that enable non-mechanical protein extraction from bacteria, yeast, plant, mammalian, and insect cells. rLysozyme™ Solution increases the efficiency of bacterial lysis with BugBuster® Reagent.

Benzonase® Nuclease, more efficient than DNAse I and other nucleases, specifically degrades contaminating DNA and RNA for the preparation of non-viscous, nucleic acid-free extracts. Lysonase™ Bioprocessing Reagent combines the functional activities of rLysozyme and Benzonase® Nuclease in an optimized, ready-to-use reagent that significantly increases protein extraction efficiency and facilitates processing of protein extracts.

Power-of-Three extraction provides the highest protein yields
Bacteria expressing recombinant 6XHis-CRP were lysed in a homebrew lysis buffer containing 20 mM Tris, pH 8, 137 mM NaCl, 10% glycerol and 1% NP-40 ± Benzonase® nuclease. Cells were also lysed with BugBuster® protein extraction reagent ± rLysozyme™ solution and ± Benzonase® nuclease.
Protein levels were measured using the Direct Detect™ infrared-based quantitation system by spotting 2 μL of lysate on a Direct Detect™ Assay-free Card and insert¬ing into the instrument. BugBuster® protein extraction reagent with both Benzonase® nuclease and rLysozyme™ solution yielded lysates with the most 6XHis-CRP. Error bars represent standard deviation of triplicate measurements.