Download: Protein Gel Guide
The most common method for in-gel protein detection is staining with Coomassie blue dye. Coomassie dye staining is especially convenient because it involves a single, ready-to-use reagent and does not permanently chemically modify the target proteins. Because no chemical modification occurs, excised protein bands can be completely de-stained and the proteins recovered for analysis by mass spectrometry or sequencing. We offer several Coomassie based protein stains that are easy-to-use and provides a simple visualization of proteins resolved by electrophoresis.
Highlights of Coomassie stains:
- Easy-to-use—simple protocols with only 2-3 steps
- Compatible—Coomassie based stains are compatible with many downstream applications such as quantitative densitometry, mass spectrometry or sequencing analysis
- Reversible
Find the right Coomassie based stain for your research needs
| Simply Blue Safe Stain | Colloidal Blue Staining | GelCode Blue Stain | GelCode Blue Safe Stain | Imperial Protein | Pageblue Protein Stain | ||
|---|---|---|---|---|---|---|---|
| Detection limit | > 7 ng | < 10 ng | 8 ng | 9 ng | ≤3 ng | 5 ng | |
| Approx. staining time (for gels) | Std | 135 min | 10 hr | 135 min | 135 min | 135 min | 95 min |
| Microwave | 12 min | 30 min | 30 min | 12 min | 30 min | ||
| # Components | 1 (Ready-to-use) | 2 | 1 (Ready-to-use) | 2 | 1 (Ready-to-use) | 1 (Ready-to-use) | |
| # of staining steps | 2 | 3 | 2-3 | 3 | 3 | 3 | |
| Staining agent | G-250 | G-250 | G-250 | G-250 | R-250 | G-250 | |
| Highlights | Non-hazardous disposal | Flexible stain for multiple applications | Non-hazardous shipping | Purple stain | Stain can be reused up to 3 times | ||
| No acid fixative or methanol required | ✓ | Methanol is required for staining, and Bis-tris gels require fixing prior to staining | ✓ *Bis-tris gels require fixing prior to staining | ✓ | ✓ | ✓ | |
| Gel staining | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |
| PVDF membrane staining | ✓ *membrane must be dry | × | ✓ | ✓ | × | ✓ *membrane must be dry | |
| Nitrocellulose membrane staining | × | × | ✓ | ✓ | ✓ | × | |
| MS or sequencing analysis | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |
| Catalog number | LC6065 | LC6025 | 24592 | 24594 | 25615 | 24620 | |
Coomassie Staining Protocol
An initial water wash step is necessary to remove residual SDS, which interferes with dye binding. Then the staining reagent is added, usually for about 1 hour with rocking. The gel can be analyzed directly in the stain. Alternatively, a water or methanol:acetic acid de-staining step can be used to wash away excess unbound dye from the gel matrix. To expedite the staining process microwaves can be used with Coomassie stains not requiring methanol or acetic acid.
Click image to enlarge
SimpleBlue SafeStain protocol
Click image to enlarge
Imperial Protein Stain Protocol
Sensitivity
3-10 microgram of protein can be detected usually within 5 minutes in Coomassie stains. With additional water-based de-staining, as little as 7 ng of protein (BSA) can be detected.
Lane 1: 6 µg protein mix
Lane 2: 1 µg rabbit IgG
Lane 3: 1 µg reduced BSA
Lane 4: 5 µg E. coli lysate
Lane 5: 20 ng reduced BSA
Lane 6: 10 ng reduced BSA
Lane 7: 7 ng reduced BSA
Lane 8: 3 ng reduced BSA
Lane 9: 10 µl Mark12 Standard
Lane 10: 5 µl Mark12 Standard
NuPAGE Bis-tris gel stained with SimplyBlue SafeStain for 1 hour and destained overnight in water.
Protein bands can be detected after 5 minutes with staining with Imperial Protein Stain. For greater sensitivity and reduced background, gels can be stained for 1 hour and de-stained overnight in water.
Linearity
Coomassie blue dyes bind proteins quantitatively within a certain protein range allowing for densitometry analysis. PageBlue protein stain can deliver a dynamic range of ~5ng to ~500ng.
PageBlue Protein Staining Solution is sensitive and has a broad, linear dynamic range. A series of samples containing beta-galactosidase and bovine serum albumin (0 to 500ng each) were separated by electrophoresis on a 12% Tris-glycine SDS-PAGE, gel, and then stained with PageBlue Protein Staining Solution and densitometry was performed on the stained protein bands.
Capture and analysis of Coomassie stained gels and membranes
iBright Imaging Systems
Capture and analyze publication quality images from stained gels and membranes with iBright Imaging Systems. These high-performance instruments enhance the imaging experience through powerful hardware, advanced automated technologies, and an interface that is easy to use for researchers of all experience levels.
Dual LED Blue/White Light Transilluminator
Illuminate your stained gels and membranes with this white light box.
Find the right Coomassie based stain for your research needs
| Simply Blue Safe Stain | Colloidal Blue Staining | GelCode Blue Stain | GelCode Blue Safe Stain | Imperial Protein | Pageblue Protein Stain | ||
|---|---|---|---|---|---|---|---|
| Detection limit | > 7 ng | < 10 ng | 8 ng | 9 ng | ≤3 ng | 5 ng | |
| Approx. staining time (for gels) | Std | 135 min | 10 hr | 135 min | 135 min | 135 min | 95 min |
| Microwave | 12 min | 30 min | 30 min | 12 min | 30 min | ||
| # Components | 1 (Ready-to-use) | 2 | 1 (Ready-to-use) | 2 | 1 (Ready-to-use) | 1 (Ready-to-use) | |
| # of staining steps | 2 | 3 | 2-3 | 3 | 3 | 3 | |
| Staining agent | G-250 | G-250 | G-250 | G-250 | R-250 | G-250 | |
| Highlights | Non-hazardous disposal | Flexible stain for multiple applications | Non-hazardous shipping | Purple stain | Stain can be reused up to 3 times | ||
| No acid fixative or methanol required | ✓ | Methanol is required for staining, and Bis-tris gels require fixing prior to staining | ✓ *Bis-tris gels require fixing prior to staining | ✓ | ✓ | ✓ | |
| Gel staining | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |
| PVDF membrane staining | ✓ *membrane must be dry | × | ✓ | ✓ | × | ✓ *membrane must be dry | |
| Nitrocellulose membrane staining | × | × | ✓ | ✓ | ✓ | × | |
| MS or sequencing analysis | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |
| Catalog number | LC6065 | LC6025 | 24592 | 24594 | 25615 | 24620 | |
Coomassie Staining Protocol
An initial water wash step is necessary to remove residual SDS, which interferes with dye binding. Then the staining reagent is added, usually for about 1 hour with rocking. The gel can be analyzed directly in the stain. Alternatively, a water or methanol:acetic acid de-staining step can be used to wash away excess unbound dye from the gel matrix. To expedite the staining process microwaves can be used with Coomassie stains not requiring methanol or acetic acid.
Click image to enlarge
SimpleBlue SafeStain protocol
Click image to enlarge
Imperial Protein Stain Protocol
Sensitivity
3-10 microgram of protein can be detected usually within 5 minutes in Coomassie stains. With additional water-based de-staining, as little as 7 ng of protein (BSA) can be detected.
Lane 1: 6 µg protein mix
Lane 2: 1 µg rabbit IgG
Lane 3: 1 µg reduced BSA
Lane 4: 5 µg E. coli lysate
Lane 5: 20 ng reduced BSA
Lane 6: 10 ng reduced BSA
Lane 7: 7 ng reduced BSA
Lane 8: 3 ng reduced BSA
Lane 9: 10 µl Mark12 Standard
Lane 10: 5 µl Mark12 Standard
NuPAGE Bis-tris gel stained with SimplyBlue SafeStain for 1 hour and destained overnight in water.
Protein bands can be detected after 5 minutes with staining with Imperial Protein Stain. For greater sensitivity and reduced background, gels can be stained for 1 hour and de-stained overnight in water.
Linearity
Coomassie blue dyes bind proteins quantitatively within a certain protein range allowing for densitometry analysis. PageBlue protein stain can deliver a dynamic range of ~5ng to ~500ng.
PageBlue Protein Staining Solution is sensitive and has a broad, linear dynamic range. A series of samples containing beta-galactosidase and bovine serum albumin (0 to 500ng each) were separated by electrophoresis on a 12% Tris-glycine SDS-PAGE, gel, and then stained with PageBlue Protein Staining Solution and densitometry was performed on the stained protein bands.
Capture and analysis of Coomassie stained gels and membranes
iBright Imaging Systems
Capture and analyze publication quality images from stained gels and membranes with iBright Imaging Systems. These high-performance instruments enhance the imaging experience through powerful hardware, advanced automated technologies, and an interface that is easy to use for researchers of all experience levels.
Dual LED Blue/White Light Transilluminator
Illuminate your stained gels and membranes with this white light box.
Resources
For Research Use Only. Not for use in diagnostic procedures.