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Protease Inhibitor Cocktail (100X)
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Protease Inhibitor Cocktail (100X) #5871

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  1. WB
Western Blotting Image 1: Protease Inhibitor Cocktail (100X)
Western blot analysis of extracts from NIH/3T3 cells, prepared in lysis buffer in the absence of protease inhibitors (left) or with Protease Inhibitor Cocktail (100X) #5871 added (right), and incubated at 37ºC for the indicated time points, using p44/42 MAPK (Erk1/2) (137F5) Rabbit mAb #4695. In the absence of protease inhibitors, p44/42 MAPK signal fades within 6 hrs. after harvest, indicating protein degradation. In the presence of the protease inhibitor cocktail, the p44/42 MAPK degradation is slowed significantly and signal is still present at 48 hrs. following harvest.

Product Usage Information

1. Briefly vortex the Protease Inhibitor Cocktail (100X) before use.

2. Just prior to lysing cells, dilute the cocktail 1:100 in desired lysis buffer to obtain a 1X working concentration.

Solutions and Reagents

The Protease Inhibitor Cocktail (100X) is composed of a proprietary mix of AEBSF, Aprotinin, Bestatin, E64, Leupeptin, and Pepstatin A to promote broad spectrum protection against endogenous proteases. The cocktail does not contain EDTA (a metalloprotease inhibitor) which can be incompatible with some downstream applications (i.e. protein assays, 2D electrophoresis, etc.). If EDTA is desired as a protease inhibitor it can be added to the cell lysis buffer at a final working concentration of 5 mM.


Store the undiluted 100X cocktail at 4ºC. Do not freeze.

Product Description

When diluted in lysis buffer to a final concentration of 1X the Protease Inhibitor Cocktail prevents protein degradation by endogenous proteases present in whole cell extract. The 100X
Protease Inhibitor Cocktail is a clear, colorless liquid.

100X Protease Inhibitor Cocktail:

80uM Aprotinin
5mM Bestatin
1.5mM E-64
2mM Leupeptin
1mM Pepstatin A


In order to study specific target proteins of interest protease-mediated degradation during the generation of protein lysates is to be avoided. A loss of normal cellular control occurs during cell lysis, and endogenous proteases within the cell extract are free to degrade proteins in an uncontrolled manner. The addition of protease inhibitors to the cell lysis buffer aids in the preservation of target proteins in the cell extract.

Limited Uses

Except as otherwise expressly agreed in a writing signed by a legally authorized representative of CST, the following terms apply to Products provided by CST, its affiliates or its distributors. Any Customer's terms and conditions that are in addition to, or different from, those contained herein, unless separately accepted in writing by a legally authorized representative of CST, are rejected and are of no force or effect.

Products are labeled with For Research Use Only or a similar labeling statement and have not been approved, cleared, or licensed by the FDA or other regulatory foreign or domestic entity, for any purpose. Customer shall not use any Product for any diagnostic or therapeutic purpose, or otherwise in any manner that conflicts with its labeling statement. Products sold or licensed by CST are provided for Customer as the end-user and solely for research and development uses. Any use of Product for diagnostic, prophylactic or therapeutic purposes, or any purchase of Product for resale (alone or as a component) or other commercial purpose, requires a separate license from CST. Customer shall (a) not sell, license, loan, donate or otherwise transfer or make available any Product to any third party, whether alone or in combination with other materials, or use the Products to manufacture any commercial products, (b) not copy, modify, reverse engineer, decompile, disassemble or otherwise attempt to discover the underlying structure or technology of the Products, or use the Products for the purpose of developing any products or services that would compete with CST products or services, (c) not alter or remove from the Products any trademarks, trade names, logos, patent or copyright notices or markings, (d) use the Products solely in accordance with CST Product Terms of Sale and any applicable documentation, and (e) comply with any license, terms of service or similar agreement with respect to any third party products or services used by Customer in connection with the Products.

For Research Use Only. Not For Use In Diagnostic Procedures.
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To Purchase # 5871
Cat. # Size Qty. Price
1 ml
$ 138