coomassie-dye-protein-gel-stains

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.

Compare different protein staining methods

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.

SimpleBlue SafeStain protocol summary
 Click image to enlarge

SimpleBlue SafeStain protocol

Imperial Protein Stain protocol summary
 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.

Sensitivity of SimplyBlue SafeStain

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.

Rapid staining with Imperial protein stain
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.

Linear dynamic range of PageBlue Protein Stain

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.

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.

SimpleBlue SafeStain protocol summary
 Click image to enlarge

SimpleBlue SafeStain protocol

Imperial Protein Stain protocol summary
 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.

Sensitivity of SimplyBlue SafeStain

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.

Rapid staining with Imperial protein stain
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.

Linear dynamic range of PageBlue Protein Stain

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.

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