Coomassie stains, also referred to as Coomassie Blue or Coomassie Brilliant Blue, are among the most widely used anionic dyes for visualizing proteins in SDS-PAGE gels. They offer reliable quantitative linearity and good sensitivity, which have made them the preferred staining method for protein identification and mass spectrometry in laboratories across the globe.
We offer Coomassie stains in three formats:
- Coomassie Brilliant Blue R-250 Protein Stain: With a molecular weight of 825.99 g/mol, this triphenylmethane dye is commonly used in SDS-PAGE for protein analysis. It binds to proteins to create a stable protein-dye complex, which maintains its negatively charged anionic form and produces a blue color, even in acidic environments. The dye is also water-soluble, with a solubility limit of 10 mM.
- Coomassie Brilliant Blue G: Brilliant Blue G offers staining sensitivity close to that of silver staining.
- Coomassie InstantBlue® Protein Stain: This is a ready-to-use, ultra-fast stain for polyacrylamide gels, delivering well-defined blue bands in just 15 minutes or less. Its single-step protocol eliminates the need for washing, fixing, or destaining, saving you valuable time and simplifying your workflow. With exceptional sensitivity, it can detect protein levels as low as 5 ng per band while maintaining a clear background for an excellent signal-to-noise ratio. Unlike traditional Coomassie stains that require overnight destaining and involve multiple steps, InstantBlue® is hassle-free and economical, needing only 25ml per mini gel, compared to 50–100ml with other stains.
This methanol and acetic acid-free formulation avoids gel shrinkage, protein methylation, or acetylation and is safe for disposal without requiring fume hoods or special solvent disposal processes. Its patented mechanism ensures rapid and reliable staining, even when gels are left in the solution for weeks, with no compromise on background clarity. InstantBlue® is compatible with mass spectrometry, making it ideal for advanced protein identification workflows.
Delivered in a convenient premixed 1 L bottle, this nontoxic solution is ready to use and has been cited in over 490 publications. The reliable and consistent batch-to-batch performance ensures excellent results for your protein analysis needs. Stored at +4°C, InstantBlue® offers convenience, safety, and outstanding performance to streamline your laboratory experiments.
Features
Key Features
- Widely used and reliable: Coomassie Blue dyes, including Brilliant Blue R-250 and InstantBlue®, are among the most popular anionic dyes for visualizing proteins in SDS-PAGE gels, offering dependable quantitative linearity and moderate sensitivity.
- Different formats for versatility: The various options support researchers by providing reliable protein staining and quick, simple protocols for efficient and accurate experimental workflows.
- High sensitivity: InstantBlue® detects protein levels as low as 5 ng per band, ensuring precise and sensitive protein analysis. Coomassie Brilliant Blue G demonstrates a high level of sensitivity, approaching that of silver staining.
- Safe and convenient: InstantBlue® has a nontoxic, methanol-free, and acetic acid-free formulation that avoids gel shrinkage, protein methylation, or acetylation. It requires no fume hood or special solvent disposal, making it safe and easy to use.
- Mass spectrometry compatibility: InstantBlue® is fully compatible with mass spectrometry, allowing seamless integration into advanced protein identification workflows.
Applications
Applications
- Electrophoresis: Used in polyacrylamide gel electrophoresis to separate and detect proteins based on molecular weight, offering a fixation-free, cost-effective, and mass-spectrometry-compatible staining method.
- Protein concentration assays: Widely applied in the Bradford assay for determining protein concentration by binding the dye to proteins.
What is Coomassie Blue used for?
Coomassie Blue is widely used as a protein stain in laboratory techniques such as SDS-PAGE and Bradford assays. It helps visualize, quantify, and analyze proteins by binding to them and forming a distinct blue complex.
How does Coomassie Blue detect proteins?
Coomassie Blue binds to proteins by interacting with their amino acid residues, forming a stable protein-dye complex. This binding results in a color change that can be measured spectrophotometrically to determine protein concentration.
What causes Coomassie brilliant blue to change its color?
The color change occurs when Coomassie Brilliant Blue binds to proteins, stabilizing its anionic form. This shift alters the dye’s absorption spectrum, resulting in the characteristic blue color.
What is the advantage of Coomassie Blue staining?
Coomassie Blue staining offers a quick, reliable, and cost-effective method for visualizing proteins in SDS-PAGE gels and other analytical techniques. It provides excellent quantitative linearity, good sensitivity, and compatibility with mass spectrometry needs, making it a preferred choice for protein analysis in research and laboratory settings worldwide.
Can Coomassie Blue be used to stain membranes in blotting applications?
Yes, Coomassie Blue can be used to stain membranes in blotting applications, although it is not the most common choice. It is typically employed as a loading control to confirm protein transfer onto the membrane. However, its sensitivity may be lower compared to other methods like Ponceau S or fluorescent stains, which are often preferred for detecting low protein concentrations on membranes.