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For years the red reversible stain Ponceau S has been the best option for those staining Western blots. Those who use Ponceau S for staining are very familiar with its major shortcomings and will welcome Pierce MemCode Reversible Protein Stain, which overcomes the disadvantages of Ponceau S-based homemade and commercial formulations.
MemCode Reversible Protein Stains offer several clear advantages over currently used formulations of Ponceau S. Table 1 compares Ponceau S and MemCode Reversible Protein Stains. MemCode Stain is without a doubt the closest to an ideal membrane stain currently available.
Table 1. Comparison of MemCode Reversible Protein Stain with Ponceau S benchmarked against the criteria for an ideal membrane stain.
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Ponceau S
Reversible Stain
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MemCode Reversible Protein Stain
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Ideal Reversible Membrane Stain for Proteins
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- Low avidity, low sensitivity general protein stain
- Detection limit:
250 ng
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- Improved avidity, higher sensitivity general protein stain
- Detection limit:
25 ng
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- High avidity for broad range of proteins
- Low nanogram range detectability
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- Resultant red bands are difficult to photograph
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- Resultant turquoise-blue bands are easily photographed
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- Absorbance in blue region of the spectrum, providing excellent photographic qualities
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- Stained protein bands fade within hours
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- Turquoise bands do not fade over time, but can be erased on demand
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- Bands remain stained until initiation of the band erasure protocol
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- Typical staining time: 5 minutes
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- Typical staining time: 30 seconds
- Background eliminated quickly with low pH wash
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- Stains proteins instantly with little or no background
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Features
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Benefits
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- All components are ready to use and easy to use
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-No reagent formulation or dilutions necessary
-Instructions and labeling designed for ease of use |
- Sensitive, high-avidity, general, protein stain
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-Comparable to Coomassie Blue Dye on a membrane
-Most bands detectable at the 25 ng level
-Bands develop in 30 seconds!
-Shown to enhance detectability of target analytes on membranes using classical Western blot protocols |
- Protein-specific stain under the conditions of the protocol
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-Avoids interference from other biomolecules such as nucleic acids, carbohydrates, lipids, etc. |
- From stain to destain to band erasure in minutes
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-Staining and destaining can be done in less than 15 minutes
-Erasing the stain can be done in less than 10 minutes |
- Turquoise bands are easily photographed
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-Absorbance in the blue region (600-650 nm) offers good properties for photo-documentation
and avoids interference from common biological chromophores |
- Stained band color does not fade with time
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-Membranes can be documented without concern of band intensity loss |
- Compatible with Western blot detection
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-Membrane treatment with MemCode Stain does not interfere with conventional
chemiluminescent or chromogenic detection using HRP and alkaline phosphatase substrates |
- Compatible with common buffers, detergents, organics, etc.
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-No interference from components common to Western blot protocols |
- Stain and erase independent of nitrocellulose membrane pore size
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-Allows use of both 0.2 µ or 0.45 µ pore size nitrocellulose in the application |
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-Kits can be stored at the bench, saving valuable refrigerator space |
 
Figure 1. Comparison of MemCode Reversible Protein Stain with Ponceau S stain. Decreasing amounts of unstained protein M.W. marker were loaded identically across two 4-20% Tris-glycine-SDS PAGE gels (Lanes 2-10). Both gels were electroblotted to nitrocellulose membrane. Blot A was treated with MemCode Stain for 30 seconds and destained according to the protocol. Blot B was stained with 0.1% Ponceau S in 5% acetic acid for 5 minutes. Some marker proteins stained that are stained with MemCode Stain are visually detectable out to eight dilutions, while those stained with Ponceau S could be detected to only five to six dilutions. Lane 1: Pierce Blue Protein MW Marker Mix (Product # 26681).
 
Figure 2. MemCode Reversible Protein Stain and Ponceau S Stain: A Comparison of GST Lysate Staining on Nitrocellulose. Increasing amounts of GST Lysate protein were loaded identically onto two 4-20% Tris-glycine SDS PAGE gels. Both gels were electroblotted to nitrocellulose membrane. Blot A was treated with MemCode Stain for 30 seconds and destained according to the protocol. Blot B was stained with 0.1% Ponceau S stain for 5 minutes and destained. The Blot stained with MemCode Stain demonstrates superior visual detection of bands. GST Lysate loading volumes (Lane 1-3). Lane1: 5 µl, Lane 2: 10 µl, Lane 3: 15 µl, Lane 4: Pierce Blue Protein MW Marker Mix (Product # 26681), 10 ml.
 
Figure 3. Comparison of GST Protein Staining between MemCode Reversible Protein Stain and Ponceau S. Different amounts of purified GST protein were loaded identically on two gels and separated on a 4-20% Tris-Glycine-SDS-PAGE gel. Both gels were electroblotted to nitrocellulose membrane. The Panel A membrane was stained using the MemCode Stain protocol for 30 seconds and destained. The Panel B membrane was stained with 0.1% Ponceau S stained for 5 minutes and destained according to the published protocol. Lane 1: 25 ng, Lane 2: 50 ng, Lane 3: 100 ng, Lane 4: 200 ng, Lane 5: 300 ng, Lane 6: 400 ng, Lane 7: 500 ng and Lane 8: MW marker.
 
Figure 4. Immunoblot Analysis of GST by Chemiluminescent Detection after MemCode Staining, Destaining and Stain Reversal. Different amounts of purified GST protein were loaded identically on two gels and separated on a 10 % Tris-Glycine-SDS-PAGE gel. Both gels were electroblotted to nitrocellulose membrane. The Control Membrane (Panel A) was not treated with MemCode Reversible Protein Stain. Panel B was subjected to the staining, destaining and stain erasing protocol of the MemCode Kit. Both membranes were then probed with Anti-GST and detected using Pierce SuperSignal West Dura Substrate (U.S. Patent # 6,432,662) after incubation with goat anti-rabbit IgG-HRP conjugate. Lane 1: 125 pg, Lane 2: 250 pg, Lane 3: 500 pg and Lane 4: 1 ng.
MemCode Reversible Protein Stain Protocol
Note: The two kits are membrane dependent. They are not interchangable.
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Certificate of Analysis
Product Instructions
MSDS