warning For Research Use Only (RUO). Not intended for clinical, diagnostic, or therapeutic use in humans.
palette Coomassie Blue · Ponceau S · Amido Black 10B
Protein Detection Stains
Three staining chemistries, one page. This is a category reference, not a product page — pick the stain your protocol calls for and click View to reach its product page. The chemistry, history, and application guidance follow below.
Protein Detection Stains — Catalog · 4 Catalog Numbers Across 3 Product Pages
This page is not a product page. Catalog numbers are grouped under the product page they order from; click View once per group.
Cat. No.
Size
Coomassie Blue Staining Solution1 catalog number · 2 x 500 mL
Protein detection stains are essential visualization tools used in biochemistry and molecular biology to identify and quantify proteins following gel electrophoresis separation. These stains employ various chemical mechanisms to make otherwise invisible protein bands visible for analysis and documentation. The ideal staining technique should offer high sensitivity, good reproducibility, wide linear dynamic range, compatibility with downstream applications, and straightforward protocols. Most staining methods involve a sequence of steps including protein fixation to prevent diffusion, exposure to the staining solution, and destaining to remove excess dye from the gel matrix background.
The five criteria above are the ones that separate the three stains stocked here — and the identity data a purchasing spec usually asks for.
Three staining chemistries stocked: Coomassie Blue Staining Solution, Ponceau S Staining Solution, and Amido Black 10B Staining Solution.
Four catalog numbers across three product pages — Ponceau S is the only one offered in two fill sizes.
Coomassie Brilliant Blue is a triphenylmethane dye; the two forms in the literature are R-250 (C.I. 42660, CAS 6104-59-2) and G-250 (C.I. 42655, CAS 6104-58-1), which differ by two methyl groups.
Ponceau S is a diazo dye — Acid Red 112, C.I. 27195, CAS 6226-79-5 — and is the standard reversible membrane stain.[6]
Amido Black 10B (Naphthol Blue Black, Acid Black 1, CAS 1064-48-8) is a diazo dye used as a general protein stain on both gels and blot membranes.[9]
Reversibility decides the workflow: Ponceau S visualizes protein on nitrocellulose without permanently fixing it, so immunoblotting or preparative elution can follow.[6]
Fixation prevents diffusion and destaining clears the gel matrix background — both are part of the staining sequence, not optional extras.
Customization is available for concentration, additions, pH, and other modifications (see the note under the reference table).
Post-ElectrophoresisGels & Blot MembranesRUO
CATEGORY REFERENCE · PROTEIN DETECTION STAINS
The catalog and the dye identities at a glance
Products in this category3
Catalog numbers4
Coomassie Blue Staining SolutionDCP-CS1X · 2 x 500 mL
Ponceau S Staining SolutionDCP-PS1X_500 mL · DCP-PS1X_1000 mL
Amido Black 10B Staining SolutionDCP-AB10B1X · 500 mL
Coomassie Brilliant Blue dye classtriphenylmethane (R-250, G-250)
Ponceau S dye identityAcid Red 112 · C.I. 27195 · CAS 6226-79-5
Amido Black 10B dye identityAcid Black 1 · CAS 1064-48-8
Ponceau S published detection limit250–500 ng protein per band[6]
Five criteria, and the one that usually decides it
The source names five properties of an ideal staining technique — sensitivity, reproducibility, linear dynamic range, downstream compatibility, and protocol simplicity. Each one is a different way a stain can cost you an experiment, and no single dye maximizes all five.
visibility
High sensitivity
How little protein still gives a visible band. Ponceau S on nitrocellulose was reported to detect 250 to 500 ng of protein, essentially the same sensitivity as Coomassie blue staining of proteins on nitrocellulose.[6] Colloidal Coomassie Brilliant Blue formulations were developed specifically to reach nanogram sensitivity in polyacrylamide gels with a clear background.[7]
repeat
Good reproducibility
The same amount of protein should give the same band on Tuesday that it gave on Monday. Dye binding depends on the local particle density of a protein in the gel, so the dye bound by an identical amount of the same protein can differ considerably depending on local concentration — a documented source of run-to-run variability.[8]
show_chart
Wide linear dynamic range
Signal has to track protein amount over a useful span. The original 1963 study established the range explicitly: protein complexes of Coomassie Brilliant Blue R250 followed Beer's law up to 20 µg/cm, with a lower detection limit of 0.5 µg/cm on electrophoretic strips.[1]
link
Downstream compatibility
The decisive criterion for blot work. Ponceau S visualizes proteins on nitrocellulose replicas without permanently fixing them to the membrane, so immunoblotting or preparative elution can follow; staining did not interfere with in-situ radioiodination or trypsin digestion.[6]
schedule
Straightforward protocols
Steps, timing, and hands-on effort. Amido Black and Ponceau S are preferred over Coomassie R on membranes because stained membranes destain quickly to leave very low backgrounds, whereas Coomassie R gives higher backgrounds.[9]
opacity
Fixation and destaining
Most staining methods run as a sequence: fixation to prevent the separated protein from diffusing out of the gel, exposure to the staining solution, then destaining to strip excess dye from the gel matrix background. Skipping fixation blurs bands; skipping destaining buries them in background.
Match the stain to what happens next, not just to what you want to see. If the band is the end of the experiment, sensitivity and dynamic range decide. If the blot goes on to immunodetection, elution, or digestion, reversibility decides — and that is a property only one of these three dyes is documented for.
250–500
ng of protein per band — published Ponceau S detection limit on nitrocellulose[6]
1963
the year Coomassie Brilliant Blue R250 was first used to estimate protein on electrophoretic strips[1]
How These Stains Became Standard
Sixty years of making invisible bands visible
Each of the three dyes on this page entered protein work at a different moment and for a different reason. The chronology explains why they are not interchangeable.
1
1963 Coomassie enters protein analysis
Fazekas de St. Groth, Webster and Datyner described two staining procedures for quantitative estimation of proteins on electrophoretic strips. The protein complexes of Procion Brilliant Blue RS and Coomassie Brilliant Blue R250 followed Beer's law up to 50 and 20 µg/cm respectively, with lower detection limits of 2 and 0.5 µg/cm — the first time a textile dye was put on a quantitative footing for protein.[1]
2
1965 Into the polyacrylamide gel
Meyer and Lamberts used Coomassie Brilliant Blue R250 for the electrophoresis of microgram quantities of parotid saliva proteins on acrylamide-gel strips — the move from cellulose acetate to the gel matrix that every modern protocol inherits.[2]
3
1970–1976 SDS-PAGE, and dye binding as an assay
Laemmli's discontinuous SDS-polyacrylamide system made band visualization a routine daily requirement rather than a specialist exercise.[3] In parallel, Bradford turned the same dye-binding chemistry into a solution assay, quantitating microgram quantities of protein on the principle of protein–dye binding.[4]
4
1979–1986 The blot, and the reversible stain it needed
Towbin, Staehelin and Gordon established electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets.[5] That created a problem the gel stains could not solve: how to see the transferred protein without destroying the blot. Salinovich and Montelaro answered it in 1986 with Ponceau S under very mild conditions, visualizing proteins on nitrocellulose replicas without permanently fixing them to the membrane.[6]
5
1988–present Colloidal chemistry and quantitative limits
Neuhoff and colleagues published improved staining of proteins in polyacrylamide gels, including isoelectric focusing gels, with a clear background at nanogram sensitivity using Coomassie Brilliant Blue G-250 and R-250.[7] Two years later the same group set out the essential problems in quantifying colloidally stained proteins and their solutions — the caveat that still governs densitometry today.[8] Ponceau S has since been re-examined as a total-protein normalization control for Western blots.[10]
Dye Reference
The three staining chemistries side by side
Chemical identity, band color, reversibility, and the substrate each dye is documented for. Use this table to translate a protocol requirement into the right catalog number.
Staining solution
Dye class & identity
Band color
Reversible on membrane
Documented substrate
Published detection limit
Coomassie Blue Staining Solution
Triphenylmethane dye. Two forms appear in the literature: R-250 (C.I. 42660, CAS 6104-59-2) and G-250 (C.I. 42655, CAS 6104-58-1), differing by two methyl groups
Blue
close Not documented as reversible; higher membrane background than Amido Black or Ponceau S[9]
Polyacrylamide gels, including isoelectric focusing gels[2,7]; also used on blot membranes[9]
Beer's law to 20 µg/cm, lower limit 0.5 µg/cm on strips (R250)[1]; nanogram sensitivity with colloidal G-250 / R-250 formulations[7]
Ponceau S Staining Solution
Diazo dye. Acid Red 112, C.I. 27195, CAS 6226-79-5
Red
check_circle Yes — proteins are visualized without being permanently fixed to the membrane[6]
Nitrocellulose replicas after SDS-PAGE and electrotransfer[6]; blot membranes generally[9]
250 to 500 ng protein per band[6]
Amido Black 10B Staining Solution
Diazo dye. Naphthol Blue Black, Acid Black 1, CAS 1064-48-8
Blue-black
close Not documented as reversible, but destains quickly to a very low membrane background[9]
Blot membranes; also one of the general protein stains used for polyacrylamide gels[9]
Not stated in the source; published values vary with protocol and membrane — consult the controlling protocol reference[9]
The source does not state which Coomassie form the solution contains. Coomassie Brilliant Blue is the name of two similar triphenylmethane dyes, R-250 and G-250, which differ by two methyl groups and are used in different ways — R-250 for direct gel staining, G-250 as the colloidal gel stain and as the Bradford solution reagent.[1,4,7] The Diagnocine source description for Coomassie Blue Staining Solution does not specify the form, so this page does not assign one. Confirm the form on the product page or with support@diagnocine.com before writing it into a protocol.
CUSTOMIZATION:Please INQUIRE if other concentrations, additions of chemicals/compounds/proteins/supplements, different pH, and modifications are needed. Contact support@diagnocine.com.
Applications by Stain
Which stain for which bench workflow
Select a stain to see the workflows it is documented for in the primary literature.
Triphenylmethane dye · blue bands · gel-first workflows
Total-protein visualization in polyacrylamide gels after electrophoretic separation[2]
Staining of isoelectric focusing gels as well as SDS gels, with a clear background when a colloidal formulation is used[7]
Quantitative estimation of protein by direct photometry, within the published linear range[1]
Densitometric quantification of stained bands, subject to the local-protein-density caveat that governs colloidal Coomassie quantification[8]
Staining of proteins on blot membranes, where higher background than Amido Black or Ponceau S should be expected[9]
Diazo dye · red bands · reversible · membrane workflows
Reversible total-protein staining of nitrocellulose replicas after SDS-PAGE and electrotransfer[6]
Confirming that transfer worked before committing a blot to immunodetection[5,6]
Locating protein bands for in-situ procedures — radioiodination and trypsin digestion for two-dimensional peptide analysis were both shown to be unaffected by prior Ponceau S staining[6]
Preparative elution of protein from the membrane after visualization, since the protein is not permanently fixed[6]
Total-protein normalization as a loading control for Western blot quantification[10]
General total-protein staining of blot membranes after electroblotting from polyacrylamide gels[9]
Protein staining in polyacrylamide gels, as one of the general protein stains used for that purpose[9]
Workflows where a very low membrane background matters more than maximum sensitivity, since Amido Black destains quickly[9]
Monitoring electrotransfer efficiency after blotting[9]
Product Comparison
How the three staining solutions compare
Catalog identity and the workflow each solution is intended for.
Product
Cat. No.
Size
Dye chemistry
Best use
Coomassie Blue Staining Solution
DCP-CS1X
2 x 500 mL
Triphenylmethane (Coomassie Brilliant Blue)
Direct staining of protein bands in polyacrylamide gels, including IEF gels, where the gel is the endpoint[2,7]
Ponceau S Staining Solution
DCP-PS1X_500 mL
500 mL
Diazo (Acid Red 112)
Reversible membrane staining when immunoblotting, elution, or digestion must follow[6]
Ponceau S Staining Solution
DCP-PS1X_1000 mL
1000 mL
Diazo (Acid Red 112)
The same workflow at higher throughput or larger membrane format[6]
Amido Black 10B Staining Solution
DCP-AB10B1X
500 mL
Diazo (Naphthol Blue Black)
General protein staining on membranes and gels where fast destaining to a very low background is the priority[9]
FAQ
Frequently asked questions
The questions that come up most often when a staining protocol meets a purchasing spec.
Ponceau S. It was introduced precisely because proteins could be visualized on nitrocellulose replicas without being permanently fixed to the membrane, which allows immunoblotting or preparative elution to be performed afterwards. Staining with Ponceau S did not interfere with in-situ radioiodination or trypsin digestion.[6] Coomassie Blue and Amido Black 10B are not documented as reversible in the same sense, although Amido Black destains quickly to a very low membrane background.[9]
Most staining methods involve a sequence of steps including protein fixation to prevent diffusion, exposure to the staining solution, and destaining to remove excess dye from the gel matrix background. Fixation stops the separated protein from diffusing out of its band after the electric field is switched off; destaining removes the dye the gel matrix itself has taken up, so the band is read against a clear background rather than a stained one.
The Diagnocine source description does not state which form the solution contains, so this page does not assign one. Coomassie Brilliant Blue is the name of two similar triphenylmethane dyes: R-250 (C.I. 42660, CAS 6104-59-2) and G-250 (C.I. 42655, CAS 6104-58-1), which differ by two methyl groups. R-250 is the classic direct gel stain,[1,2] G-250 is used in colloidal gel stains[7] and as the reagent of the Bradford solution assay.[4] Confirm the form on the product page or with support@diagnocine.com before writing it into a protocol.
On nitrocellulose they are comparable. The Ponceau S technique was reported to detect 250 to 500 ng of protein, which is essentially the same sensitivity seen for Coomassie blue staining of proteins on nitrocellulose.[6] In polyacrylamide gels the comparison is different: colloidal Coomassie Brilliant Blue G-250 and R-250 formulations were developed to give a clear background at nanogram sensitivity.[7]
Within limits, and the limits are documented. The ideal staining technique should offer a wide linear dynamic range, and the original Coomassie work established one explicitly: protein complexes of Coomassie Brilliant Blue R250 followed Beer's law up to 20 micrograms per centimetre, with a lower detection limit of 0.5 micrograms per centimetre.[1] For colloidal staining, the local particle density of a protein in a given gel determines its stainability, so dye binding to the same amount of the same protein differs considerably with local concentration — which is why quantitative densitometry needs the controlling correction procedures.[8]
Ponceau S is the standard choice. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets[5] leaves you needing to see the transferred protein without destroying the blot, and Ponceau S under very mild conditions does exactly that.[6] It is also used as a total-protein normalization control for Western blot quantification.[10] Amido Black 10B is the alternative where a fast destain to a very low membrane background is wanted.[9]
Yes. Please INQUIRE if other concentrations, additions of chemicals, compounds, proteins or supplements, different pH, and modifications are needed. Send the requirement to support@diagnocine.com.
Key References
Primary literature behind the three stains
Every specification, detection limit, and application claim on this page traces to one of the entries below. Each was checked against the primary record before it was written.
Fazekas de St. Groth S, Webster RG, Datyner A (1963). Two new staining procedures for quantitative estimation of proteins on electrophoretic strips. Biochim Biophys Acta 71:377–391. doi:10.1016/0006-3002(63)91092-8
Meyer TS, Lamberts BL (1965). Use of Coomassie brilliant blue R250 for the electrophoresis of microgram quantities of parotid saliva proteins on acrylamide-gel strips. Biochim Biophys Acta 107(1):144–145. doi:10.1016/0304-4165(65)90403-4
Laemmli UK (1970). Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227:680–685. doi:10.1038/227680a0
Bradford MM (1976). A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72:248–254. doi:10.1016/0003-2697(76)90527-3
Towbin H, Staehelin T, Gordon J (1979). Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci USA 76(9):4350–4354. doi:10.1073/pnas.76.9.4350
Salinovich O, Montelaro RC (1986). Reversible staining and peptide mapping of proteins transferred to nitrocellulose after separation by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Anal Biochem 156(2):341–347. doi:10.1016/0003-2697(86)90263-0
Neuhoff V, Arold N, Taube D, Ehrhardt W (1988). Improved staining of proteins in polyacrylamide gels including isoelectric focusing gels with clear background at nanogram sensitivity using Coomassie Brilliant Blue G-250 and R-250. Electrophoresis 9(6):255–262. doi:10.1002/elps.1150090603
Neuhoff V, Stamm R, Pardowitz I, Arold N, Ehrhardt W, Taube D (1990). Essential problems in quantification of proteins following colloidal staining with Coomassie Brilliant Blue dyes in polyacrylamide gels, and their solution. Electrophoresis 11(2):101–117. doi:10.1002/elps.1150110202
Goldman A, Harper S, Speicher DW (2016). Detection of proteins on blot membranes. Curr Protoc Protein Sci 86:10.8.1–10.8.11. doi:10.1002/cpps.15
Sander H, Wallace S, Plouse R, Tiwari S, Gomes AV (2019). Ponceau S waste: Ponceau S staining for total protein normalization. Anal Biochem 575:44–53. doi:10.1016/j.ab.2019.03.010
