CHES Buffer (0.2 M, pH 9.0, Sterile) - BioReagent

Cat. No.: C1528877

GRADE & PURITY BioReagent

Storage

Store at 2-8°C

Shipped In

Wet ice

Panoramica

CHES buffer, whose active component is 2-(Cyclohexylamino)ethanesulfonic acid, is a classic reagent in the Good's buffer series. As a zwitterionic buffer, it exhibits excellent buffering capacity in the pH range of 8.6 to 10.0 (with a pKa of approximately 9.3–9.5 at 25°C). This product is supplied as a ready-to-use sterile liquid, composed of CHES and deionized water, and sterilized by autoclaving. It is suitable for research applications requiring high cleanliness standards.

Specifications

Specifiche e purezza

BioReagent

Condizioni di conservazione di stoccaggio

Store at 2-8°C

Spedito in

Wet ice

Questo prodotto richiede spedizione a catena fredda. I servizi di terra e altri servizi economici non sono disponibili.

Grado

BioReagent

Product Line

Prodotti biologici

Application Protocols

• General use as stock buffer (item-specific context: 0.2 M, pH 9.0, sterile)

  1. Equilibrate to room temperature if precise pH at use temperature is required; gently mix.
  2. For working buffer (e.g., 50 mM), dilute with sterile water or appropriate sterile diluent (see Buffer Applications). Mix thoroughly.
  3. Verify pH at the measurement temperature; adjust slightly if necessary with sterile acid/base (e.g., HCl/NaOH) using aseptic technique.
  4. If adding salts or cofactors, dissolve completely and re-check pH and clarity. Filter sterilize (0.22 μm) if sterility must be ensured after additions.

• Example: Preparing 500 mL of 25 mM CHES, pH 9.0

  • Combine 62.5 mL of 0.2 M stock with 437.5 mL sterile water. Mix and confirm pH.

• Notes for analytical workflows

  • For UV/fluorescence assays, run a buffer blank to establish baseline since item-specific UV cutoffs are not provided.
  • For LC/CE, verify system compatibility at pH 9.0 and assess any required filtration/degassing.

• Sterile handling

  • Work in a clean environment (e.g., biosafety cabinet) if sterility must be maintained. Use sterile vessels and pipette tips. Minimize open time to reduce contamination risk.

Biological Roles

• Nature of the buffer (literature)

  • CHES is one of Good’s buffers, designed for minimal biological reactivity, low membrane permeability, and low metal binding. It does not participate in known metabolic pathways and is used to maintain extracellular/in vitro pH rather than to exert biological effects.

• Impact on biomolecules (literature/general)

  • Proteins/enzymes: Provides pH stability near 9.0 with limited interaction with enzyme active sites compared to primary amine buffers like Tris. Nonetheless, the secondary amine can compete in amine-coupling reactions—avoid use in such workflows.
  • Nucleic acids: Typically inert with DNA/RNA; suitable for alkaline-dependent steps where mild basicity is tolerated. Verify for applications sensitive to ionic strength.
  • Metal cofactors: Exhibits relatively low chelation; suitable for many metalloenzymes when compared to buffers with stronger complexation tendencies (e.g., phosphate, borate in certain contexts).

• Cell culture and biological systems

  • Not a nutrient or osmolyte; used ex vivo/in vitro for biochemical assays. For live-cell work, confirm osmolarity and compatibility; this product is a 0.2 M stock and generally requires dilution to typical working strengths (10–100 mM).

Buffer Applications

• Supplied format (item-specific): 0.2 M CHES, pH 9.0, sterile. Use directly as a stock to prepare working-strength buffers.

• Typical working concentrations (literature/general)

  • 10–100 mM for enzyme assays and general biochemistry; select concentration based on buffering capacity needs and ionic strength tolerance.

• Dilution guidelines from 0.2 M stock (examples; verify pH after dilution)

  • 1 L of 50 mM buffer: mix 250 mL of 0.2 M stock with 750 mL water (sterile if needed).
  • 1 L of 25 mM buffer: mix 125 mL stock with 875 mL water.
  • 100 mL of 20 mM buffer: mix 10 mL stock with 90 mL water.
  • After dilution, confirm pH at working temperature; minimal adjustment may be needed due to temperature/ionic effects.

• Additives and compatibility

  • Salts (e.g., NaCl, MgCl2, CaCl2) may be added as required; re-check pH. CHES has low metal binding (literature), but validate for sensitive metalloenzyme assays.
  • Avoid for amine-reactive labeling (e.g., NHS ester or aldehyde-based conjugations) where the buffer’s amine can quench reactions.
  • For spectroscopic assays, run a buffer blank to confirm baseline as item-specific UV data are not provided.

• Sterility and asepsis

  • Product is sterile; use sterile technique and sterile diluents/containers to maintain sterility. If sterile filtration is required post-additive, use 0.22 μm PES or equivalent and verify compatibility.

Green Alternatives

As an aqueous, ready-to-use buffer, this product already aligns with green chemistry principles for benign solvents/media. Selection among buffers focuses on reducing hazards, waste, and interferences.

• Comparative overview (literature)

  • CHES vs Tris: CHES has less CO2 sensitivity and a higher effective pH range; Tris is widely available but exhibits significant temperature and CO2 dependence, potentially causing rework and waste.
  • CHES vs CAPS: CAPS buffers higher pH (pKa ~10.4) but can exhibit higher background in some spectroscopic assays; CHES suits mid-alkaline work with lower risk of interference.
  • CHES vs Borate: Borate can complex cis-diols and some metals, potentially perturbing systems; CHES shows minimal complexation, reducing unintended side reactions.

• Sustainability considerations

  • Ready-to-use sterile solution reduces on-site chemical handling of powders and minimizes pH-adjustment waste.
  • Long shelf-life at 2–8 °C (item-specific storage) can reduce remakes; confirm actual expiry on CoA.

• Simple comparison (qualitative, literature)

  • Criteria: CO2 sensitivity (low for CHES), metal binding (low), spectral background (low), buffering window (pH ~8.6–10.0), biocompatibility (good). Trade-offs include potential interference with amine-reactive chemistries due to the buffer’s amine group.

Pharmaceutical Uses

• Scope

  • For research use only (item-specific). Not for human or veterinary use.

• Formulation and process development (general, non-clinical)

  • CHES buffers are occasionally explored in pre-formulation and process development to study stability of drug substances and biologics at alkaline pH. The low metal binding and spectroscopic background (literature) can aid analytical characterization.
  • As a 0.2 M sterile stock, this product can streamline buffer screening matrices, minimizing preparation variability in DoE studies.

• Compatibility considerations

  • Assess excipient interactions: CHES contains a secondary amine (literature), which can interact with aldehyde-containing impurities or activated esters; avoid for products relying on amine-based conjugations.
  • Material compatibility: At pH 9, confirm compatibility with container/closure systems (e.g., certain elastomers) and analytical flow paths.

• Regulatory status

  • No pharmacopeial grade or monograph is claimed in this listing. Endotoxin, bioburden, residual solvent, or elemental impurity limits: Not specified for this item; refer to CoA/Spec Sheet if required for your quality system.

Physical Properties

• Item-specific properties (as supplied)

  • Concentration: 0.2 M CHES (aqueous)
  • pH (25 °C, nominal): 9.0
  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Density, refractive index, conductivity, UV cutoff, metal content: Not specified for this item; refer to CoA/Spec Sheet.

• General properties (literature, for CHES buffer systems)

  • pKa (CHES, 25 °C; literature): ~9.3–9.5 (buffers effectively ~pH 8.6–10.0)
  • Solubility (CHES free acid/salt; literature): highly soluble in water; negligible solubility in nonpolar solvents.
  • Ionic character: zwitterionic/ionic; low membrane permeability; minimal temperature-dependent pKa drift among Good’s buffers.
  • Temperature coefficient (ΔpKa/°C; literature): small and positive for CHES; expect modest pH rise with decreasing temperature.

• Compatibility and miscibility

  • Fully miscible with water; miscible with common aqueous biological media and salts; miscible with water-miscible organics (e.g., methanol) in limited proportions depending on application (verify pH after mixing).

Notes:

• Numerical values not listed under item-specific properties are not provided for this product; consult the CoA/Spec Sheet for measured specifications. Literature values are given for scientific context and method planning.

Quality and Grades

• Grade (item-specific): BioReagent

  • BioReagent grade generally indicates suitability for common biological research workflows, with controlled bioburden and low levels of interfering impurities for routine enzymology and biochemical assays.
  • This product is supplied as a sterile, ready-to-use 0.2 M aqueous buffer at pH 9.0 to minimize variability and preparation errors.

• What is and is not specified for this item

  • Sterility: supplied sterile (item-specific). Maintain aseptic technique to preserve sterility after opening.
  • Concentration and pH: 0.2 M, pH 9.0 (item-specific).
  • Trace metals, UV absorbance profile, DNase/RNase/protease activity, endotoxin: Not specified for this item; refer to CoA/Spec Sheet.
  • Stabilizers/preservatives: Not specified for this item; refer to CoA/Spec Sheet.

• Practical implications

  • Ready-to-use format supports reproducibility in pH-sensitive assays near pH 9.
  • If low-fluorescence or LC-MS–compatible buffer is needed, confirm background levels and additives on the CoA, as these are not specified here.

• Documentation

  • For lot-specific values (e.g., exact pH at 25 °C, conductivity, sterility tests), consult the CoA/SDS. No additional item-specific analytical specifications are provided in this listing.

Reaction and Applications

Primary utility is as a biological buffer at alkaline pH; it is not generally used as a reagent in synthetic organic transformations.

• Biochemical and analytical applications (literature/general)

  • Enzyme assays operating optimally near pH 9 (e.g., certain dehydrogenases, hydrolases) where amine-containing buffers like Tris may interfere.
  • Electrophoresis and isoelectric focusing in alkaline regimes; compatible with many proteins due to low metal binding and low absorbance.
  • Sample preparation and dilution for alkaline pH extraction steps in analytical workflows; supports stability of some analytes at pH ~9.
  • Capillary electrophoresis and HPLC aqueous phases requiring controlled pH ~9 (check instrument material compatibility and UV background).

• Practical guidance

  • Use as supplied for 0.2 M stock; prepare working buffers by dilution (see Buffer Applications). Always verify pH at the measurement temperature.
  • Avoid in reactions or assays using amine-reactive chemistries (e.g., NHS ester labeling, aldehyde crosslinkers) where the secondary amine in CHES (literature) may compete.
  • For metalloenzyme studies, CHES is favored over strongly chelating buffers; nevertheless, verify cofactor stability experimentally.

• Expansion on manufacturer applications

  • No specific applications were listed in the catalog entry; the above represent common, literature-supported uses of CHES buffers in life-science research.

Reaction Conditions

Because this product is an aqueous biological buffer rather than a reagent, “reaction conditions” primarily relate to its use environment.

• Working ranges (literature/general)

  • Effective buffering window: approximately pH 8.6–10.0 (CHES pKa ~9.3–9.5 at 25 °C).
  • Temperature: commonly used from 4–37 °C in biochemical assays; verify pH at working temperature due to small temperature coefficient.
  • Ionic strength: Can be adjusted with salts; confirm effects on protein stability and enzyme kinetics.

• Solvent and additives

  • Water as the principal solvent; limited volumes of water-miscible organics (e.g., ≤10% v/v methanol/acetonitrile) may be tolerated in analytical workflows—verify assay tolerance and pH.

• Practical performance tips

  • Degassing is typically unnecessary; if required for sensitive optical or electrochemical measurements, mild vacuum or helium sparge can be used, then re-check pH.
  • For metalloenzyme catalysis, pre-equilibrate buffer with the intended metal ion and confirm no loss of activity, given CHES’s low but nonzero interaction potential (literature).

• Yields/kinetics

  • No item-specific kinetic data or reaction yields are applicable. For enzyme kinetics in CHES, consult organism/enzyme-specific literature and validate under your exact conditions.

Safety and Handling

• GHS/SDS status for this specific item

  • Signal word / Hazard statements / Pictograms / GHS classification: Not specified for this item; refer to the product SDS for authoritative safety information.

• General laboratory handling (good practice)

  • This is an alkaline aqueous buffer (pH 9.0). Avoid contact with eyes/skin; may cause irritation.
  • Recommended PPE: lab coat, safety glasses, and appropriate chemical-resistant gloves (e.g., nitrile). Use in a clean environment to maintain sterility if aseptic work is required.
  • First aid (general guidance): rinse skin/eyes with water for at least 15 minutes in case of contact; if ingested, rinse mouth and seek medical advice; if inhaled as aerosol, move to fresh air. Always follow institutional SOPs and consult the SDS.

• Incompatibilities and precautions (general)

  • Avoid mixing with strong acids or strong bases that could significantly shift pH; verify pH after adding salts or cosolvents.
  • CHES contains a secondary amine (literature); avoid unintended reactions with amine-reactive chemistries (e.g., NHS esters) used in bioconjugation workflows.
  • Maintain sterility: handle under aseptic conditions if the buffer is to remain sterile after opening.

• Storage and transport

  • Store at 2–8 °C (item-specific). Shipments are on wet ice (item-specific). Prevent freezing unless validated for your application.

Always defer to the SDS and institutional risk assessments for final hazard classifications and emergency measures.

Solvent Selection

This product is an aqueous buffer; traditional solvent selection is not applicable in the same way as for organic reagents. Key considerations relate to aqueous compatibility and cosolvent tolerance.

• Polarity and medium

  • Highly polar, ionic, water-based solution; ideal for aqueous biochemistry at alkaline pH.

• Miscibility and cosolvents

  • Fully miscible with water. Small percentages of water-miscible organics (e.g., methanol, ethanol, acetonitrile, DMSO) are sometimes added in assays; verify pH after addition and confirm biological compatibility.

• When to choose CHES vs alternatives (literature)

  • Choose CHES for buffering in the pH 8.6–10.0 range when minimal metal binding, low absorbance in UV–vis, and limited biological reactivity are desired.
  • Alternatives: Tris (pKa ~8.1; more temperature/CO2 sensitive), TAPS (pKa ~8.4), CAPS (pKa ~10.4) for slightly more alkaline conditions.

• Practical tips

  • If using high ionic strength or cosolvents, re-check pH at working temperature; Good’s buffers have modest temperature coefficients, but pH 9 systems are sensitive to dilution and temperature.
  • For spectroscopic assays, confirm baseline absorbance/fluorescence with your instrument since item-specific UV cutoffs are not provided.

Storage and Reconstitution

• Storage conditions (item-specific)

  • Store at 2–8 °C. Shipments are on wet ice. Protect from contamination. Do not use if turbidity, precipitate, or color change is observed unless validated.

• Freeze–thaw guidance

  • Freezing is generally not necessary for this aqueous buffer and may lead to pH drift or container stress; store refrigerated as directed. If freezing is required for your workflow, validate performance post-thaw and mix thoroughly before use.

• Reconstitution

  • Not applicable; this is a ready-to-use sterile solution. For working concentrations, dilute with sterile water or compatible sterile diluent, then verify pH at working temperature.

• Shelf life and stability

  • Expiry dating, sterility assurance period, and lot-specific stability data: Not specified for this item; refer to CoA/Spec Sheet.

• Handling after opening

  • Maintain aseptic technique to preserve sterility. Aliquot into sterile containers to minimize repeated openings. Label aliquots with preparation and expiry dates per your quality system.

• Disposal

  • Dispose of aqueous buffer waste according to institutional and local regulations. Neutralize if required by your facility’s procedures prior to drain disposal.

Structure and Identity

This product is a ready-to-use aqueous buffer solution: CHES Buffer, 0.2 M, pH 9.0 (sterile). Item-specific identifiers for the solution are not supplied.

• Item-specific identifiers

  • Molecular formula (solution): Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight (solution): Not applicable to a mixture; refer to CoA/Spec Sheet if needed.
  • SMILES/InChIKey (solution): Not applicable to a mixture.

• Buffering species (literature, for context): CHES = 2-(cyclohexylamino)ethanesulfonic acid

  • Typical molecular formula (free acid; literature): C8H17NO3S
  • Typical molecular weight (free acid; literature): ~207.29 g/mol
  • Structural features (literature): secondary amine linked via an ethyl spacer to a sulfonic acid (–SO3H) group; cyclohexyl ring confers hydrophobic character; zwitterionic near neutral–alkaline pH.
  • 2D description (literature): a cyclohexyl ring bonded to –NH–CH2–CH2–SO3H; no stereocenters; no aromatic rings; contains one tertiary sulfonyl sulfur and one secondary amine nitrogen.

• Category/Type: Good’s buffer (biological buffer), alkaline range.

Note: Structural data above describe the neat buffering agent (literature) and are provided for scientific context only; the product itself is an aqueous, sterile 0.2 M solution at pH 9.0.

Synthetic Utility

This material is supplied and intended as an aqueous biological buffer; it has limited direct use in synthetic organic chemistry.

• Potential utility (literature/general)

  • As a controlled-pH medium for aqueous-phase transformations or biocatalysis operating near pH 9.0.
  • In chemoenzymatic syntheses where enzyme stability requires an alkaline, low-chelating buffer.

• Limitations

  • The secondary amine functionality of CHES (literature) may react with acylating agents, activated esters (e.g., NHS esters), and aldehydes; thus, it is generally unsuitable as a medium for amine-sensitive reactions.
  • Not commonly used as a nucleophilic catalyst or base in synthesis due to its buffering design and sulfonic acid moiety.

• Retrosynthetic perspective

  • CHES offers no particular synthetic handle for downstream diversification in this supplied format; choose alternative reagents (e.g., tertiary amines or carbonate buffers) when nucleophilic base catalysis or non-coordinating media are required.

Target Specificity

Not applicable. This product is a chemical buffer solution, not a biological targeting reagent (e.g., antibody, ligand, or inhibitor). No antigen/epitope, species reactivity, clone, or isotype information applies.