Methylene Blue Staining Solution (0.1%) - BioReagent

Cat. No.: M1528786

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

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Visão geral

Methylene Blue (also known as Methylthioninium Chloride) has the molecular formula C₁₆H₂₄ClN₃O₃S (hydrated), MW 373.9, CAS 7220-79-3. This product is a 0.1% aqueous solution, ready to use. It is commonly used for staining silk, paper, bacteria, and cells, and is also suitable for yeast viability staining (live cells appear colorless due to reduction; dead cells appear blue). Due to the dye’s susceptibility to oxidation, stained preparations are not stable for long-term preservation. Store at room temperature in a sealed container, protected from light; shelf life: 12 months. For research use only.

Specifications

Especificações e pureza

BioReagent

Condições de armazenamento de armazenamento

Room temperature

Enviado em

Normal

Grau

BioReagent

Product Line

biological_products

Application Protocols

The following protocols are provided as general literature guidance for 0.1% aqueous methylene blue solutions. They are not validated specifically for this SKU; optimize for your samples.

• Simple bacterial smear stain (literature)

  1. Prepare heat-fixed bacterial smear on a clean glass slide and allow to cool.
  2. Flood the smear with 0.1% methylene blue solution for 60–120 seconds.
  3. Rinse gently with distilled water until runoff is nearly colorless.
  4. Blot dry with lint-free tissue and air-dry. Examine under brightfield microscopy (1000× oil immersion if needed).

• Wet-mount plant tissue contrast (literature)

  1. Place a thin section of leaf or root on a slide with a drop of water.
  2. Add 1–2 drops of 0.1% methylene blue to the edge of the coverslip; draw through with capillary action using a tissue.
  3. After 1–3 minutes, gently flush with water to reduce background, as desired. Image immediately.

• Gel/biopolymer visualization (screening; literature)

  1. Immerse hydrogel or membrane in 0.1% methylene blue for 5–15 minutes with gentle agitation.
  2. Rinse extensively with water/buffer to remove unbound dye; quantify retained color by reflectance or extraction followed by absorbance at ~660–668 nm.

Notes

• Filter the solution (0.22–0.45 μm) if particulates interfere with imaging.
• Adjust staining time based on sample thickness and fixation. Overstaining can be corrected by prolonged rinsing.

Biological Roles

• Binding interactions (literature)

  • As a cationic phenothiazinium dye, methylene blue associates with polyanionic biomolecules—particularly nucleic acids—via electrostatic attraction and intercalative/stacking interactions. This underlies its utility for visualizing nuclei and chromatin-rich regions in fixed specimens.

• Redox chemistry in biological contexts (literature)

  • Methylene blue forms a reversible redox couple with leucomethylene blue. In the presence of cellular reductants or redox enzymes, the dye can be reduced and subsequently re-oxidized by oxygen, providing a basis for certain viability and redox-activity assays.

• Photobiology (literature)

  • Upon visible-light irradiation, methylene blue can act as a photosensitizer to produce reactive oxygen species (e.g., singlet oxygen) in aerated aqueous media. This property is leveraged in photodynamic experiments and caution is warranted to avoid unintended photooxidation during sample handling.

• Cellular staining behavior (literature)

  • In simple staining of bacteria, MB enhances contrast by coloring cells against a light background. In some histological workflows, it can act as a counterstain for acidic tissue components.

Note: These biological roles are general literature descriptions of methylene blue and are not specific performance claims for this item. This product is for research use only (not for use in humans or animals for therapeutic/diagnostic purposes).

Buffer Applications

This product is a staining solution rather than a buffering agent, so it is not typically used to establish or maintain pH.

• Practical notes
  • If your protocol specifies staining in a buffered environment (e.g., PBS, phosphate buffer, or Tris), you may dilute the staining solution into the desired buffer—confirm compatibility and composition first, as this item’s buffer components (if any) are not specified.
  • Rinsing with the same medium used during staining (water vs. buffer) can reduce precipitation or edge effects on slides.

For pH-controlled applications or electrophoresis buffers, select a dedicated buffer system (e.g., phosphate, Tris, HEPES) appropriate to your target pH and ionic strength.

Green Alternatives

• Environmental and safety profile (general)

  • Aqueous methylene blue solutions avoid volatile organic compounds and generally pose lower inhalation risk than solvent-borne stains. However, the intense color demands careful waste management to prevent aesthetic and potential ecotoxic concerns.

• Potential greener or alternative choices (literature/guidance)

  • Toluidine blue O: another cationic dye, often effective at lower concentrations for plant tissues; similar handling profile.
  • Safranin O: commonly used counterstain; may be preferable for certain plant histology with comparable aqueous handling.
  • Food dyes (e.g., Brilliant Blue FCF) for educational demonstrations where minimal hazard is prioritized; not suitable for all research-grade applications.
  • For photoredox catalysis, organic dyes such as eosin Y or riboflavin tetraacetate may offer different redox windows and biodegradability; selection depends on reaction requirements.

• Comparison snapshot (general, literature)

  • Methylene blue vs. crystal violet: MB typically considered less problematic regarding mutagenic intercalation concerns than some triarylmethane dyes, but still handle with care and avoid environmental release.
  • Aqueous vs. alcoholic formulations: Aqueous media reduce flammability and VOCs; alcoholic solutions can improve wetting but increase fire risk and exposure.

• Practical green tips

  • Use minimal effective contact times and volumes; collect colored rinses for appropriate waste treatment.
  • Protect from light to extend solution lifetime and reduce waste from photodegradation.
  • Where feasible, implement micro-staining protocols to minimize reagent consumption.

Pharmaceutical Uses

No pharmaceutical or clinical uses are claimed or supported for this catalog item. It is intended for research use only.

• General context (literature/industry)

  • Methylene blue has historically been employed as a colorant and analytical dye and is monographed in certain pharmacopeias in defined contexts. Such information is provided as background only and does not confer suitability of this specific staining solution for any manufacturing or clinical application.

• Formulation considerations for research settings

  • For device or material coloration studies, the intense visible absorbance of methylene blue can be used to visualize diffusion and release profiles in aqueous media.
  • If considering use in a regulated manufacturing environment, consult compendial standards and obtain detailed specifications and change controls; this product does not provide those assurances unless explicitly stated in its CoA/Spec Sheet.

Always restrict use of this product to non-clinical laboratory research.

Physical Properties

• Item-specific properties (this catalog item)

  • Appearance, pH, density, refractive index, UV cutoff: Not specified for this item; refer to CoA/Spec Sheet.
  • Being an aqueous 0.1% solution, bulk properties are expected to be similar to water; exact values not specified.

• Typical properties of methylene blue solutions (literature/general)

  • Color/optics: Intense blue; methylene blue shows strong absorption with λmax ≈ 660–668 nm in water (literature) with high molar absorptivity (ε ≈ 70,000–90,000 M−1 cm−1, literature; value depends on ionic strength and pH).
  • Redox behavior: Reversibly reduced to colorless leucomethylene blue by reducing agents; re-oxidizes in air/with oxidants (literature).
  • Photochemical behavior: Photosensitizer under visible light; can generate singlet oxygen in aerated media (literature).

• Computed/concentration considerations for a 0.1% w/v dye solution (general calculation)

  • If 0.1% w/v corresponds to 1.0 mg/mL methylene blue chloride, the molar concentration would be ~3.13 mM (1.0 mg/mL ÷ 319.85 g/mol) as a theoretical value. Actual concentration for this item depends on exact salt/content; refer to CoA for confirmation.

• Solubility (literature)

  • Methylene blue is readily soluble in water and alcohols; limited solubility in nonpolar solvents due to its cationic nature.

• Stability notes (literature)

  • Aqueous solutions are generally stable at room temperature away from strong light and reducing agents. Prolonged light exposure can lead to photobleaching/photoreactions.

All quantitative values above are literature/general guidance and not item-specific specifications.

Quality and Grades

• Supplied grade (item-specific): BioReagent.

• What BioReagent typically implies (general guidance)

  • Suitable for common life-science laboratory procedures (e.g., routine staining, visualization) where consistent performance and low background are important but where ultra-trace analyses are not the focus.
  • Emphasis on reproducible staining characteristics, low particulate matter, and solution clarity. UV background at analytical wavelengths is typically not a limiting parameter for microscopy stains.

• Relevance to methylene blue staining solutions

  • For microscopy and teaching/research labs, BioReagent grade supports consistent color intensity and minimal precipitate formation that could interfere with imaging.
  • If your application is highly sensitive to ionic content (e.g., electrophysiology, specialized spectroscopy), verify acceptable conductivity and any additives via the CoA/Spec Sheet.

• Stabilizers and additives

  • Not specified for this item; refer to CoA/Spec Sheet. Some commercial dye solutions may include preservatives or buffering components—confirm before use in live-cell or enzyme-sensitive contexts.

• Batch-to-batch assurance

  • For critical staining quantitation, record lot numbers and, if needed, establish an internal QC such as absorbance at 660–668 nm for a defined pathlength and dilution. This can help normalize between lots without relying on unspecified vendor metrics.

• Regulatory/trace data

  • Metal content, microbial limits, and specific contaminant thresholds are not specified for this item; consult the CoA if such data are needed for your workflow.

Reaction and Applications

• Primary application domain (this item)

  • Ready-to-use staining reagent for microscopy and general laboratory visualization. Typical uses include simple staining of bacterial smears, highlighting nuclei/acidic structures in some tissues, and contrasting plant cells. Exact validated applications for this specific SKU are not listed; see Application Protocols for general literature procedures.

• Staining mechanisms (literature)

  • Methylene blue is a cationic (basic) dye. It binds preferentially to anionic biomolecules (e.g., nucleic acids, acidic polysaccharides) via electrostatic interactions and π–π stacking with aromatic bases, yielding strong blue coloration. In viable/non-viable assays, its redox activity can differentiate metabolically active cells when paired with appropriate reductants.

• Ancillary laboratory applications (literature)

  • Redox indicator: color change upon reduction (blue → colorless) is used to track reducing environments.
  • Photosensitizer: under visible light, can catalyze photooxidations (e.g., singlet-oxygen-mediated transformations) in water or mixed solvents.
  • Tracer dye: visualization of fluid paths and leak detection due to intense coloration.

• Practical tips (general)

  • Filtering through a 0.22–0.45 μm membrane can reduce particulate background before critical imaging.
  • Control staining time and rinse thoroughly to minimize nonspecific background. For smears, typical contact times are 30 s to several minutes depending on fixation and sample composition (see Application Protocols).
  • Avoid strong reducers (dithionite, ascorbate) during staining; they can decolorize the dye, complicating interpretation.

Reaction Conditions

As a staining reagent, this item is normally used at ambient conditions. For users leveraging methylene blue’s chemical reactivity, the following are general literature conditions (not item-specific):

• Photoredox transformations (literature)

  • Light source: red or broad visible LEDs; emission overlapping 650–670 nm improves excitation efficiency.
  • Solvents: water, alcohols (MeOH, EtOH), or water–acetonitrile mixtures; oxygenated conditions for aerobic oxidations, deoxygenated for certain reductions.
  • Catalyst loading: 0.1–2 mol% methylene blue relative to substrate; adjust based on light intensity and pathlength.
  • Temperature: ambient (20–25 °C) is common; cooling may be used to control exotherms.
  • Reaction time: minutes to hours depending on substrate and light flux.

• Redox indicator use (literature)

  • Concentrations: μM–low mM dye levels are sufficient to visualize endpoint/redox state.
  • Reducing agents: sodium dithionite, glucose/enzymatic systems; avoid carryover if color persistence is required.

• Staining operations (general practice)

  • Contact time: typically 30 s to 5 min for smears; up to 10–15 min for thicker specimens. Rinse thoroughly with water or buffer to remove excess dye.
  • Temperature: room temperature; elevated temperatures generally unnecessary and may increase nonspecific staining.

Note: These are general guidelines. Optimize case-by-case and confirm compatibility with your substrates and matrices. This product does not specify validated reaction conditions.

Safety and Handling

• GHS/SDS information

  • Signal word, hazard statements, pictograms, and GHS classification: Not specified for this item; refer to the product SDS for authoritative safety data.

• General hazards (literature/typical for methylene blue solutions)

  • May cause skin and eye irritation and persistent staining of skin, nails, and labware.
  • Harmful if swallowed in quantity; avoid ingestion and inhalation of aerosols.
  • Environmental: strong coloration—prevent release to drains to avoid aesthetic contamination of effluents.

• PPE and handling

  • Wear lab coat, safety glasses, and appropriate chemical-resistant gloves (e.g., nitrile). Use good laboratory hygiene to prevent staining.
  • Work with care to avoid splashes; consider secondary containment and bench protection during microscopy staining workflows.

• Incompatibilities and reactivity (literature)

  • Reducing agents (e.g., dithionite, ascorbate) can decolorize the dye by forming leucomethylene blue; strong oxidants may degrade the chromophore.
  • Photosensitizer: under light and oxygen, can generate reactive oxygen species; store away from intense light to minimize photochemical reactions.

• First-aid overview (general guidance; defer to SDS)

  • Skin: wash with soap and water; staining may persist temporarily.
  • Eyes: rinse cautiously with water for several minutes; remove contact lenses if present and easy to do.
  • Ingestion/inhalation: seek medical advice if large amounts are involved; rinse mouth, move to fresh air.

Always consult the SDS for comprehensive hazard, exposure controls, and disposal guidance.

Solvent Selection

This product is supplied as a ready-to-use aqueous staining solution; independent solvent selection is generally not required.

• Medium characteristics (general)

  • Primary solvent: water (typical for methylene blue staining solutions), though exact composition for this item is not specified; refer to CoA/Spec Sheet.
  • Polarity/miscibility: fully miscible with water and aqueous buffers; readily dilutable to match protocol requirements.

• When solvent considerations may matter

  • For fixed-tissue or smear staining, use as provided or dilute with deionized water. If a buffered environment is needed (e.g., to control ionic strength or pH during staining), verify compatibility and composition before mixing, as buffering components for this item are not specified.
  • For applications in organic media or mixed solvents (e.g., photoredox catalysis or materials dyeing), prepare fresh dilutions of the solution into the desired solvent or use solid dye to better control concentration and solvent composition.

• Alternatives

  • If background staining is problematic, consider using filtered, freshly prepared dye solutions and rinse with the same solvent system (e.g., water or buffer) to minimize precipitation and edge effects.

• Comparison (general guidance)

  • Water vs. buffer (PBS/Tris): Buffers can stabilize pH-sensitive samples but may change ionic interactions and staining affinity. Choose water to keep interactions simple; choose buffer to improve reproducibility when sample pH is critical.

Storage and Reconstitution

• Storage (item-specific)

  • Storage conditions: Room temperature (per Product Data).
  • Shipping: Normal (per Product Data).

• General handling and stability (literature/guidance)

  • Protect from strong light to minimize photodegradation and unintended photosensitized reactions; store in the original, tightly closed container—amber packaging is preferred for light-sensitive dyes.
  • Avoid contamination with strong reducing agents (which decolorize) and strong oxidizers (which can degrade the dye).
  • If precipitate or stratification is observed, warm gently to ambient temperature and mix thoroughly (vortex or invert) until homogeneous. Discard if persistent turbidity or microbial growth is evident.

• Reconstitution

  • Not applicable; this is a ready-to-use solution. If concentration adjustment is required, dilute with deionized water (or a validated buffer if your protocol demands controlled pH/ionic strength). Composition details of this item beyond the dye content are not specified; verify compatibility before buffer dilution.

• Freeze–thaw

  • Freezing is not generally necessary for aqueous dye solutions and may lead to container stress or precipitation; store at room temperature as directed.

Always refer to the product label and CoA/Spec Sheet for lot-specific guidance and to the SDS for safe handling and disposal.

Structure and Identity

This product is a ready-to-use aqueous staining solution containing 0.1% methylene blue for general biological staining in research workflows.

• Item-specific identifiers (this catalog item)

  • CAS, InChIKey, SMILES: Not specified for this item; refer to CoA/Spec Sheet.
  • Grade: BioReagent (see Quality & Grades tab).
  • Solution description: 0.1% staining solution; exact solvent/buffer composition not specified for this item; refer to CoA/Spec Sheet.

• Active dye identity (literature, for background)

  • Common name: Methylene Blue (MB), also known as Basic Blue 9.
  • Typical salt form: methylene blue chloride (thionine dye family).
  • Molecular formula (MB chloride, literature): C16H18ClN3S
  • Molecular weight (MB chloride, literature): 319.85 g/mol
  • SMILES (literature): CN(C)c1ccc2nc3ccc(cc3[s+]2)c1N.Cl[−]
  • InChIKey (literature, chloride): WATHXJDOKTZGQF-UHFFFAOYSA-M
  • Structural features: a planar, tricyclic phenothiazinium cation bearing two dimethylamino substituents; typically isolated with chloride as counterion. Conjugated aromatic system imparts intense blue color; exists in reversible redox pair with leucomethylene blue (colorless, reduced form).

• 2D structure (described): Two benzene rings fused via a sulfur- and nitrogen-bridged central thiazine ring (phenothiazine core). Para-dimethylamino substituent on one ring and an amino substituent on the other; the ring nitrogen is quaternized (cationic), balanced by a chloride anion in the common salt form.

Note: The exact counterion, impurities, and any stabilizers for this product are not specified; consult the CoA for definitive identity data.

Synthetic Utility

While primarily supplied as a biological stain, methylene blue has documented utility in chemical synthesis and analysis (literature):

• Photoredox catalysis

  • Acts as an organic photoredox catalyst under visible light, enabling aerobic oxidations, C–H functionalizations, and reductive dehalogenations in water or mixed solvents. The strong absorption around 660–668 nm allows excitation with red LEDs. Catalyst loadings typically 0.1–2 mol% (literature), often in the presence of sacrificial electron donors or oxygen.

• Redox mediator/indicator

  • Serves as an electron shuttle in electrochemical setups, and as a redox indicator in titrations or reaction monitoring (blue ↔ colorless transitions).

• Materials and polymer chemistry

  • Employed to sensitize polymerizations or crosslinking under light exposure and to probe diffusion/porosity in hydrogels and membranes.

Practical note: This SKU is an aqueous 0.1% solution. For exacting synthetic applications, users may prefer weighing solid methylene blue to define molarity and select solvent, or they may volumetrically dispense and further dilute this solution, accounting for its initial concentration (see Physical Properties for a theoretical conversion). Verify impurities, counterions, and additives via CoA before incorporating into sensitive reaction systems.

Target Specificity

Not applicable. This product is a chemical staining solution and not an antibody or affinity reagent. No antigen/epitope specificity, clone, isotype, or species reactivity data are associated with this item.