Methylene Blue Staining Solution (1%) - BioReagent

Cat. No.: M1528798

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Vue d’ensemble

Methylene Blue, also known as Methylthioninium Chloride, has the molecular formula C₁₆H₂₄ClN₃O₃S (hydrated), with a molecular weight of 373.9 and CAS No. 7220-79-3. This product is a 1% aqueous solution of Methylene Blue, ready for immediate use. It is commonly employed for staining silk, paper, bacterial smears, and cellular samples for microscopic observation. Due to the dye's susceptibility to oxidation, stained preparations are not suitable for long-term preservation.

Specifications

Spécifications et pureté

BioReagent

Conditions de stockage de stockage

Room temperature

Expédié en

Normal

Grade

BioReagent

Product Line

Produits biologiques

Application Protocols

The following are general, literature-based protocols for using a 1% methylene blue staining solution. Optimize conditions for your specimens and instrumentation.

1. Agarose gel post-staining (DNA/RNA)

• After electrophoresis, gently agitate the gel in enough 1% solution to cover it (5–10 mL per cm² gel) for 10–30 min.
• Rinse in distilled water with gentle rocking; replace water every 5–10 min until background sufficiently clears (typically 15–60 min total). Visualize bands under white light or a standard transilluminator.

2. Bacterial or yeast simple stain (fixed smears)

• Prepare a thin smear on a clean slide; air-dry and heat-fix or methanol-fix per SOP.
• Flood with 1% methylene blue for 30–120 s.
• Rinse gently with water, blot dry, and examine by brightfield microscopy (1000× oil immersion as needed).

3. Cytology smear counterstain

• Following primary stain/fixation, apply 1% methylene blue for 30–60 s.
• Rinse in water, air-dry, and mount.

4. Quick viability check (qualitative)

• Mix a small aliquot of cell suspension with the dye (method-dependent). Assess uptake/exclusion rapidly by microscopy. Validate against a reference method; not all cell types behave similarly.

Notes:

• Protect solutions and stained specimens from intense light to avoid photoreduction.
• If excessive background occurs, increase rinse time or use brief alcoholic rinses, recognizing that alcohol can alter morphology.
• Exact timings depend on specimen thickness and matrix; run a timing ladder on first use.

Biological Roles

This product is intended for laboratory staining and not for biological administration. The following describes the dye’s interactions in research contexts (literature/general), not clinical use.

• Binding behavior: Methylene blue is a cationic, planar aromatic dye that associates with polyanionic biomolecules (e.g., nucleic acids, acidic polysaccharides) via electrostatics and π–π interactions. This leads to preferential coloration of nuclei and RNA-rich regions in fixed cells and tissues.
• Redox activity: The dye participates in reversible redox cycling between oxidized (blue) and reduced (leuco, colorless) forms. In biological assays, this property underpins its use as a redox indicator for metabolic or enzymatic processes in vitro.
• Photosensitization: Under visible light, methylene blue can generate reactive oxygen species; this is exploited in photodynamic inactivation studies for microorganisms in controlled research settings.
• Cellular uptake: The cationic nature facilitates uptake into some cellular compartments depending on membrane potential and fixation/permeabilization conditions; staining intensity can be modulated by ionic strength and pH of the medium.
• Compatibility: In fixed samples, methylene blue generally provides good contrast with minimal specialized handling. In live-cell contexts, protocols vary and require careful optimization to avoid confounding effects from redox or photosensitization.

Note: No medical or clinical claims are made for this product. For all biological uses, optimize staining conditions empirically and include appropriate positive/negative controls.

Buffer Applications

While not a buffering agent, the staining performance of methylene blue is influenced by the composition of the surrounding medium. Practical guidance (literature/general):

• Aqueous buffers: Phosphate-buffered saline (PBS), Tris-buffered saline (TBS), or distilled water are commonly used for rinsing and diluting when needed. Ionic strength and pH can modulate electrostatic interactions; mildly acidic conditions may enhance contrast for some tissues.
• Gel staining: For agarose gels, post-electrophoresis staining is often performed in water to reduce salt background, followed by destaining in multiple water changes to increase band contrast. Buffers can be used but may slow destaining.
• Smears and sections: Brief immersion in 1% methylene blue, followed by thorough water rinse, yields crisp nuclear staining; buffer choice affects background—use low-salt rinses for higher specificity.
• Interference: Strong anionic detergents (e.g., SDS) in the matrix or rinse can compete with dye binding and reduce intensity.

Example working sequences (general):

• Agarose gels: Stain in 1% solution for 5–30 min with gentle rocking; rinse in water, replacing every 5–10 min until background is acceptable.
• Microbial smears: Fix (methanol or heat per SOP), stain 30–120 s, rinse with water, air-dry, and examine.

Exact pH and buffer composition for this catalog item are Not specified for this item; refer to CoA/Spec Sheet.

Green Alternatives

From a green chemistry perspective, a pre-made 1% methylene blue staining solution offers several advantages and tradeoffs.

Potential advantages:

• Aqueous, low-VOC medium (typical for methylene blue staining), minimizing flammability and solvent exposure versus organic-based stains (literature/general).
• Ready-to-use format reduces weighing/handling of powders, decreasing particulate exposure and lab waste from repeated solution prep.
• The dye is effective at low loadings; rinses can be performed with water, reducing reliance on organic destainers.

Considerations and tradeoffs:

• Aquatic toxicity and coloration of effluents warrant appropriate waste capture and treatment to prevent dye release to drains.
• Alternative dyes may offer higher sensitivity, enabling lower dye mass per experiment but can introduce different hazard profiles.

Comparison (general literature):

• Methylene blue vs. ethidium bromide for gels: MB avoids mutagenic intercalators and works in water, but sensitivity is lower and background can be higher without careful destaining.
• Methylene blue vs. crystal violet/safranin: MB can substitute as a basic dye with an aqueous profile; some alternatives may require alcohol-rich formulations and present higher toxicity.

Greener practice tips:

• Use minimal bath volumes and adopt small staining trays sized to the specimen.
• Reuse staining solution for compatible applications until performance declines; filter particulates to extend life.
• Collect spent solutions for dye-specific disposal; consider activated carbon or advanced oxidation in institutional waste treatment where available.

Pharmaceutical Uses

This product is supplied as a laboratory BioReagent staining solution for research use only. It is not manufactured to GMP standards and is not intended for human or veterinary use.

Contextual information (literature/general):

• Methylene blue (methylthioninium chloride) exists as a pharmacopeial substance for certain medicinal and diagnostic contexts; however, those uses require specific compendial grades, GMP manufacturing, and stringent release testing not implied by this listing.
• In pharmaceutical laboratories, methylene blue solutions may be used in non-clinical settings such as device leak testing, visualizing flow paths, or as a tracer in process development experiments.

Formulation/excipient role for this specific item:

• Not applicable. This 1% staining solution is intended for bench-top analytical and staining tasks, not as an excipient or API.

Regulatory note:

• Users in regulated environments should procure appropriate compendial grades and follow relevant pharmacopeial monographs if clinical or manufacturing use is contemplated. This product is for research use only.

Physical Properties

Item-specific physico-chemical specifications for the supplied 1% staining solution are not provided.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Solution composition: Not specified for this item; refer to CoA/Spec Sheet.
• Density, pH, refractive index, viscosity: Not specified for this item; refer to CoA/Spec Sheet.

Relevant literature properties for the dye component (methylene blue) — for context only:

• Typical absorption maximum (λmax, water): ~660–665 nm; intense blue color (literature).
• Secondary absorption: ~610 nm shoulder (literature).
• Molar extinction coefficient: ~70,000–80,000 M⁻¹·cm⁻¹ at λmax, depending on ionic strength and pH (literature).
• Solubility: Freely soluble in water and polar protic solvents; forms cationic monomers/dimers depending on concentration and ionic strength (literature).
• Acid–base behavior: Exists predominantly as a cation over a wide pH range; spectral properties can shift with pH and redox state (literature).
• Redox properties: Reversible redox couple between oxidized blue form and colorless leuco form; acts as an electron-transfer mediator (literature).

Practical notes:

• The observed color intensity of a 1% solution provides a convenient visual indicator for pipetting and staining progress.
• Spectral verification (e.g., peak at ~664 nm) can be used for QC of working solutions, but any acceptance criteria for this catalog item are Not specified for this item; refer to CoA/Spec Sheet.

Quality and Grades

• Supplied grade: BioReagent.

What BioReagent typically signifies (general guidance):

• Intended for laboratory research and biochemical workflows, with attention to functional performance in biological staining or assay contexts.
• Emphasis on reliability, low bioburden, and consistent staining performance, rather than ultra-trace analytical purity or LC–MS background.
• UV/Vis behavior, background staining, and lot-to-lot consistency are prioritized for such ready-to-use solutions.

What is item-specific:

• This product is a 1% staining solution, designed for direct use without further dilution for common visualization tasks. Exact composition (solvent system, buffering, preservatives/stabilizers if any) is Not specified for this item; refer to CoA/Spec Sheet.
• Storage at room temperature and shipment under normal conditions simplifies logistics without cold-chain requirements.

What is not specified and should be verified by users if critical:

• Trace metal content, microbial limits, UV cutoff, pH, stabilizers/preservatives, and solvent identity/concentration: Not specified for this item; refer to CoA/Spec Sheet.

Practical QA recommendations:

• Record lot numbers and run a quick functional QC (e.g., test stain on a standard smear or gel) when receiving new lots.
• If your application is spectroscopic or quantitative, verify absorbance at λmax and background at the wavelength(s) of interest for your assay.
• For regulated environments, obtain the CoA and method validation data aligned with your internal SOPs.

Reaction and Applications

Primary use of this product: laboratory staining. The 1% methylene blue solution is broadly useful for rapid visualization in biological and materials contexts.

Common staining applications (general literature):

• Nucleic acids: Post-stain agarose gels to visualize DNA/RNA without intercalating mutagens; sensitivity is modest, but bands are visible after short incubations and water destaining.
• Microbiology: Simple staining of bacteria and yeast for cell morphology counts; can serve as a counterstain in certain differential protocols.
• Histology/cytology: Basic dye that preferentially stains acidic cellular components, highlighting nuclei and RNA-rich regions in smears or imprints.
• Viability assessments: In some protocols, differential uptake/exclusion provides a quick qualitative readout (method-dependent; verify with controls).

Ancillary chemistry applications (literature):

• Redox indicator: Color change to colorless leuco form under reducing conditions; useful in teaching labs and certain titrations.
• Photoredox mediator: Acts as an organic photocatalyst under visible light for single-electron transfer in synthetic reactions and pollutant degradation studies.

Practical tips:

• Gentle agitation improves staining uniformity; use clean, dye-resistant containers.
• Rinse thoroughly to reduce background. For gels, cycles of short water washes enhance band contrast.
• Protect from strong light to limit photoreduction that can alter apparent staining intensity.

Reaction Conditions

No reaction conditions are specified for this catalog item, which is supplied as a staining solution. The following is general literature guidance for methylene blue used as a reagent/catalyst in research chemistry.

Photoredox catalysis (literature examples):

• Solvents: Water, MeOH, EtOH, or mixtures; often compatible with benign conditions.
• Light source: Visible light (blue or white LEDs); intensity tuned to avoid over-reduction. Typical irradiance 10–50 mW/cm².
• Catalyst loading: 0.1–2 mol% relative to substrate when used as a photocatalyst; concentration dependence affects self-quenching and dimerization.
• Atmosphere: Aerobic for oxidative processes (leveraging O2), inert/reducing for reductive sequences.
• Temperature: Ambient (20–30°C) common; cooling may be used to control exotherms under high irradiance.
• Time/yields: Reaction times from 0.5–24 h depending on substrate; yields reported from moderate to high depending on mechanism and quenchers.

Redox indicator/titrations (literature):

• Work in aqueous media; track color change from blue to colorless (leuco) near endpoints in reducing titrations. Maintain gentle stirring and minimal headspace oxygen when the reduced form is required.

Analytical adsorption studies (literature):

• Prepare standard curves by diluting the stock solution; monitor at ~664 nm. Use clean cuvettes to minimize adsorption losses.

For any critical application, validate with small-scale trials, as the exact composition of this product is Not specified for this item; refer to CoA/Spec Sheet.

Safety and Handling

Hazard classification for this specific formulation is not provided.

• GHS classification, signal word, pictograms, H-statements: Not specified for this item; refer to SDS.

General safety guidance (good laboratory practice; consult the SDS for authoritative information):

• PPE: Wear lab coat, appropriate chemical-resistant gloves, and safety glasses or face protection. The dye strongly stains skin, porous materials, and labware; dedicated equipment is recommended.
• Engineering controls: Use in a well-ventilated area; avoid creating aerosols or splashes. Protect benches with absorbent pads.
• Handling: Avoid contact with skin and eyes. Cap tightly when not in use to prevent contamination and evaporation. Protect from strong light to minimize photoreduction to leuco-methylene blue in transparent vessels.
• Incompatibilities: Strong oxidizers/reductants can alter dye oxidation state; anionic surfactants or polyelectrolytes may affect binding to biological substrates. Avoid contact with bleaches (can cause decolorization and byproducts).
• First aid (overview): In case of skin contact, wash with soap and water. For eye contact, rinse cautiously with water for several minutes; remove contact lenses if present and easy to do. If inhaled (mists), move to fresh air. If ingested, rinse mouth. Seek medical attention for persistent irritation or exposure concerns. Follow institution protocols.
• Spill response: Absorb with inert material; solutions can be decolorized with reducing agents followed by appropriate neutralization if permitted by local regulations. Dispose of waste in accordance with institutional and governmental regulations.
• Fire safety: Aqueous staining solutions are typically nonflammable; use extinguishing media suitable for surrounding materials.

Solvent Selection

This product is supplied as a ready-to-use 1% staining solution; external solvent selection is generally not required for routine use.

General considerations when working with methylene blue solutions (literature and best practice):

• Polarity and miscibility: Methylene blue is highly water-soluble and mixes readily with aqueous buffers and many lower alcohols. Co-solvents (e.g., ethanol) can alter tissue permeability and staining kinetics.
• Ionic strength and pH: Buffer composition and ionic strength affect electrostatic binding to substrates (e.g., nucleic acids, acidic polysaccharides). Slightly acidic conditions often enhance contrast on some tissues; verify empirically.
• Destaining/ rinsing: Water or buffered saline typically suffices. Alcoholic rinses accelerate removal from loosely bound sites but may also reduce contrast.
• Compatibility: Avoid strong anionic detergents in staining baths when electrostatic binding is desired; they can disrupt dye–substrate interactions.

When to choose alternatives:

• For nucleic acid visualization in agarose gels, safer nucleic acid–specific dyes may provide higher sensitivity; methylene blue prioritizes nontoxic handling and aqueous work-up but is less sensitive.
• For rapid bacterial Gram staining steps, crystal violet and safranin are used in the canonical protocol; methylene blue can substitute as a counterstain in some workflows depending on organism and visualization needs.

Storage and Reconstitution

• Storage conditions (as supplied): Room temperature (per product data). Store tightly capped.
• Shipping: Normal (no special temperature control required per product data).
• Light sensitivity: Protect from strong light to minimize photoreduction to leuco-methylene blue and potential fading.
• Freeze–thaw: Not applicable for typical aqueous staining solutions; avoid freezing unless specified on the CoA/Spec Sheet, as precipitation or container rupture may occur.
• Reconstitution: Not required; this is a ready-to-use 1% staining solution.
• Homogeneity: If any precipitation or stratification is observed, mix thoroughly by gentle inversion. If persistence is noted, warm to ambient and re-mix. Do not use if insoluble particulates remain.
• Contamination control: To maintain performance, avoid returning used solution to the stock container. Dispense working volumes into clean secondary vessels. Consider aliquoting for routine use.
• Compatibility: Use glass or dye-resistant plastics; methylene blue can stain and adsorb to some polymers and silicone.
• Shelf life: Not specified for this item; refer to CoA/Spec Sheet. As a best practice, record first-open date and monitor for changes in color intensity, precipitate formation, microbial growth, or odor.
• Disposal: Collect spent solutions as dye-containing aqueous waste. Dispose in accordance with institutional and local regulations.

Research use note: For research use only (per product data).

Structure and Identity

This product is a ready-to-use 1% staining solution of the phenothiazinium dye commonly known as methylene blue (methylthioninium chloride), formulated for laboratory staining applications.

• SKU: M1528798
• Product name: Methylene Blue Staining Solution (1%)
• Grade: BioReagent
• CAS, CID, InChIKey, SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula and molecular weight (solution): Not specified for this item; refer to CoA/Spec Sheet.

General structural information (literature, for the dye component):

• Core scaffold: A planar, tricyclic phenothiazine ring system (thiazine fused to two benzene rings) bearing a delocalized cation.
• Functional groups: Two dimethylamino substituents on the aromatic system; the dye is typically isolated as the chloride salt (counterion varies by grade/source).
• Charge state: Cationic (phenothiazinium) chromophore balanced by an anion (commonly Cl−).
• Conjugation: Extended aromatic conjugation confers a strong absorption band in the red/near-IR region, giving an intense blue color.
• Stereochemistry: None (achiral, planar polycyclic cation).

2D structure in words (literature): A central sulfur- and nitrogen-containing thiazine ring is fused to two benzene rings (phenothiazine). Para to the heteroatoms, dimethylamino groups donate electron density into the conjugated system, stabilizing the cationic resonance forms. The chloride counterion is not covalently bound and is solvated in aqueous media.

Synthetic Utility

Although primarily provided here as a staining solution, methylene blue is a versatile reagent in synthetic and analytical chemistry (literature/general):

• Organic photoredox catalyst: The dye’s excited states under visible light enable single-electron transfer, facilitating oxidative or reductive transformations (e.g., aerobic oxidations of sulfides, amine functionalizations, dehalogenations) in water or mixed aqueous media.
• Redox mediator/indicator: Employed in electrochemical and analytical setups to shuttle electrons between substrates and electrodes; useful in teaching labs for redox titrations (e.g., visualization of end points via leuco/oxidized interconversion).
• Photosensitizer in environmental chemistry: Catalyzes generation of reactive oxygen species for dye degradation studies and advanced oxidation processes—useful as a model compound for photocatalyst benchmarking.
• Polymer and material science: Serves as a cationic probe to quantify surface charge density or porosity (adsorption studies on clays, carbons, and membranes), with isotherm fitting (Langmuir/Freundlich) yielding capacity metrics.

Practical notes if using this item in chemistry settings:

• The 1% solution format simplifies handling; however, exact solvent composition and additives are Not specified for this item; refer to CoA/Spec Sheet. If additives interfere with your reaction, prepare fresh solutions from neat dye of known purity.
• Control light exposure to maintain the oxidation state; degassing or oxygenation can steer redox direction as needed.
• Be mindful of dye adsorption to glass or plastics at low concentrations, which can affect quantitative work.

Target Specificity

This product is not an antibody, probe, or affinity reagent with defined molecular target specificity. It is a general cationic dye that binds broadly to polyanionic substrates via electrostatic and aromatic interactions.

• Antigen/epitope, species reactivity, clone, isotype: Not applicable.

Application guidance:

• For nucleic acid and cell staining, specificity arises from physicochemical interactions rather than sequence or epitope recognition. Include appropriate controls (unstained, counterstained) to confirm interpretability in your assay context.