What does a Coomassie stain tell you?
Coomassie Blue stain is used to stain the protein bands in polyacrylamide gels. One common way to use it is to dissolve the dye in a mixture of methanol, acetic acid, and water. This stain will permeate the gel, stain the protein, and also fix the protein in place.
What does Coomassie based dye stain?
Coomassie R-250 and G-250 dyes are two chemical forms of a disulfonated triphenylmethane compound that is commonly used as the basis of stains for detection of proteins in gel electrophoresis and Bradford-type assay reagents for protein quantitation.
How does Coomassie staining work?
The Coomassie dyes (R-250 and G-250) bind to proteins through ionic interactions between dye sulfonic acid groups and positive protein amine groups as well as through Van der Waals attractions. Solutions of the dye, dark blue black at pH 7, turn a clear tan upon acidification.
Why do you need to wash the gel before staining it?
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; finally, a water or simple methanol: acetic acid destaining step is used to wash away excess unbound dye from the gel matrix.
Is Coomassie blue negative?
Coomassie brilliant blue (CBB) stain is a widely used method for routine visualization of proteins separated on polyacrylamide gels. The stain transfers an overall negative charge to the proteins allowing their separation from the polyacrylamide gel. …
Is silver staining quantitative?
Silver staining has a narrow linear dynamic range (the range at which the level of staining is linear to the concentration), making it less suitable for quantification.
Which is the best bio safe Coomassie stain?
Bio-Safe™ Coomassie (161-0786) — Bio-Safe Coomassie Brilliant Blue G-250 stain is fast, simple, sensitive, and convenient. Premixed, ready-to-use, nonhazardous solution No methanol or acetic acid required for destaining Bio-Safe composition reduces solvent waste disposal costs
How are Coomassie dyes used in Bio-Rad?
Bio-Rad offers Coomassie stains in three major formats. Coomassie blue dyes are a family of dyes commonly used to stain proteins in SDS-PAGE gels. The gels are soaked in dye, and excess stain is then eluted with a solvent (“destaining”).
Do you need acetic acid fixation for Coomassie stain?
Choose the flexibility of Bio-Safe Coomassie Premixed Staining Solution. Proteins can be visualized in polyacrylamide gels with or without the use of acetic acid/methanol fixation. * Fixation is recommended for peptide and very low molecular weight protein separations prior to using Bio-Safe Coomassie Stain.
Where can I get a Coomassie premixed stain number?
If you are an educator at the K–12 or college level, contact your local Customer Service office to establish an education account number. Choose the flexibility of Bio-Safe Coomassie Premixed Staining Solution. Proteins can be visualized in polyacrylamide gels with or without the use of acetic acid/methanol fixation.