Phosphate Buffer (pH 7.6, Dehydrated) (ChP) - BioReagent

Cat. No.: P1528305

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Overview

For pharmaceutical dilution

Specifications

Specifications & Purity

BioReagent

Storage

Room temperature

Shipped In

Normal

Grade

BioReagent

Product Line

Biological Products

Application Protocols

General laboratory protocol for reconstituting and using a dehydrated phosphate buffer at pH 7.6 (non-item-specific; confirm against label/CoA):

• Reconstitution:
  • Add the dehydrated contents to a clean beaker containing ~80–90% of the final desired volume of purified water (≥18 MΩ·cm).
  • Stir until fully dissolved. Rinse the package to transfer any remaining solids.
  • Bring to final volume with water. Allow to equilibrate to 20–25 °C and verify pH.
• Optional adjustments (if permitted by your method):
  • Fine-tune pH with dilute NaOH or H3PO4. Avoid large corrections that change ionic strength.
  • Add NaCl or surfactant (e.g., Tween 20) if required by the application; these are not included unless specified.
• Clarification/sterilization:
  • Filter through 0.45 µm for clarification or 0.22 µm for sterile applications. Use low-protein-binding membranes for protein work.
• Use in workflows (examples):
  • Immunoassays: Use as wash/dilution buffer after adding required salts/surfactants/proteins per SOP.
  • Chromatography: Equilibrate columns with reconstituted buffer; monitor conductivity/pH.
  • Enzyme assays: Prepare substrate and enzyme stocks; mix in buffer to desired final concentrations; record temperature and pH. Note: No item-specific tested applications/dilutions are provided; refer to your internal SOPs and validate for your system.

Biological Roles

• Physiological relevance (general knowledge): Phosphate is central to cellular biochemistry: energy metabolism (ATP/ADP/AMP), phosphorylation signaling, nucleic acid backbone structure, and mineralized tissues (hydroxyapatite). Intracellular and extracellular fluids are buffered near neutrality, with phosphate contributing to buffering capacity.
• Buffering regime: At pH 7.6, the H2PO4−/HPO4²− pair provides effective buffering around neutral pH, relevant for many enzymatic processes conducted in vitro.
• Metal interactions: Phosphate can coordinate metals and form sparingly soluble salts with Ca²⁺, Mg²⁺, Mn²⁺, etc., influencing enzyme activity and solution clarity; this is a key consideration in biochemical assays and cell-free systems.
• Nucleic acids/proteins: Phosphate buffers are widely used for protein stabilization and nucleic acid handling due to low UV absorbance and minimal interference in many spectrophotometric assays.
• Osmotic/ionic effects: Ionic strength from phosphate salts contributes to macromolecular stability and reaction rates. Final ionic strength should be tuned for the specific biological system. Note: These are general roles of phosphate in biochemistry; the exact performance depends on the item’s formulation and working concentration (not specified here).

Buffer Applications

This product is purpose-built as a dehydrated phosphate buffer targeting pH 7.6 upon reconstitution.

• Preparation (item-specific guidance with non-specified parameters clearly noted):
  • Dissolve the entire contents in the volume of purified water indicated on the product label to obtain the intended buffer concentration and pH. Specific mass-per-liter and target molarity: Not specified for this item; refer to product label/CoA.
  • Mix until fully dissolved; allow the solution to equilibrate to measurement temperature (typically 20–25 °C) before verifying pH.
  • If protocol permits minor adjustments, fine-tune pH with dilute NaOH or H3PO4; avoid large adjustments that change ionic strength markedly.
• Sterility: For sterile applications, pass the reconstituted solution through a 0.22 µm membrane filter into a sterile vessel. Autoclaving suitability: Not specified for this item; consult CoA/SDS or validate.
• Typical working ranges (literature/general): Phosphate buffers are commonly used at 5–100 mM around pH 6.5–8.0. At pH 7.6, buffering capacity is strong and temperature sensitivity is modest.
• Additives (as needed, not included unless stated): NaCl (e.g., physiological 0.15 M) for isotonicity, nonionic detergents (e.g., 0.05–0.1% Tween 20) for washes, protein stabilizers (BSA, gelatin) for immunoassays. Validate compatibility with your application.
• Compatibility cautions:
  • Avoid high concentrations of Ca²⁺/Mg²⁺ to prevent phosphate precipitation.
  • Phosphate may inhibit some enzymes or interact with metal cofactors; verify performance for sensitive assays.

Green Alternatives

Phosphate buffer is generally considered a benign, low-toxicity, water-based system. Its environmental consideration centers on phosphate discharge into wastewater (eutrophication potential), not worker exposure or VOCs.

• Greenness profile (general):
  • Aqueous, non-flammable, non-volatile; minimal worker exposure risks compared with organic buffers/solvents.
  • Mineral nutrients (phosphate, sodium/potassium) — avoid uncontrolled release to prevent algal blooms.
• Alternatives and trade-offs (literature/general):
  • HEPES/MOPS/Good’s buffers: Minimal metal interactions, excellent biological compatibility; higher cost, potential persistence in the environment, and not nutrient-limited like phosphate.
  • Bicarbonate/CO2 buffering: Highly biocompatible for cell culture with controlled CO2; requires gas control and exhibits higher pH drift without it.
  • Tris: Widely used; amine reactivity can interfere with some derivatizations and enzyme systems; larger temperature coefficient than many Good’s buffers.

Comparison (general guidance):

• Phosphate (this item): Inorganic, strong buffer near pH 7.6; watch Ca²⁺/Mg²⁺ precipitation; manage wastewater nutrient load.
• HEPES: Stable pH over temperature, low metal binding; more expensive, wastewater considerations differ.
• Bicarbonate/CO2: Green and biogenic; requires CO2 atmosphere control to maintain pH.

Pharmaceutical Uses

For research, development, and manufacturing support only; not for human or veterinary use.

• Typical roles (general/industry practice):
  • Process buffers for purification steps (chromatography equilibration/wash/elution when phosphate-compatible), dilution, and formulation development studies near neutral pH.
  • Analytical sample preparation for methods requiring low UV background.
  • Excipient studies: Phosphate is a common buffering excipient in parenteral and oral formulations due to well-characterized safety and stability profiles; use here is limited to research and process development unless lot-specific pharmacopeial compliance is documented.
• ChP note: The “(ChP)” notation in the name indicates alignment with the Chinese Pharmacopoeia context. For this specific item, explicit monograph compliance is Not specified for this item; refer to CoA/Spec Sheet. Verify compendial suitability (ChP/Ph. Eur./USP) per lot if required.
• Regulatory and quality considerations:
  • Document water quality, filtration, and bioburden control for GMP-like studies.
  • Evaluate extractables/leachables from contact materials if used in process-scale buffers.
  • Confirm endotoxin/bioburden levels where relevant; item-specific limits are not provided here.

Physical Properties

• Appearance (as sold): Not specified for this item; refer to CoA/Spec Sheet. Dehydrated phosphate buffers are generally free-flowing crystalline or granular powders.
• Solubility (literature/general): Highly water-soluble; designed to fully dissolve in purified water to prepare the target buffer. Insoluble in nonpolar organic solvents.
• pH: Target pH 7.6 after reconstitution (item-specific tolerance not specified; verify after dissolution and temperature equilibration).
• Ionic strength/osmolality: Not specified for this item; refer to CoA/Spec Sheet. These parameters depend on the intended molarity and any added salts (e.g., NaCl) in the formulation.
• Buffer system pKa (literature): Phosphoric acid pKa2 ≈ 7.20 at 25 °C (pKa1 ≈ 2.15; pKa3 ≈ 12.35). The pH 7.6 operating point is on the H2PO4−/HPO4²− pair, affording good buffering around neutral pH.
• Temperature coefficient (literature): Phosphate buffer shows a modest negative ΔpH/ΔT near neutrality (approximately −0.002 to −0.003 pH units per °C); confirm experimentally for critical applications.
• Density, refractive index, conductivity (solution): Not specified for this item; refer to CoA/Spec Sheet. Values depend on final concentration and salt identity.
• UV cutoff/background (solution): Not specified for this item; refer to CoA/Spec Sheet. Phosphate generally has low UV absorbance above 210–220 nm (literature), enabling use in many UV-detected assays.

Quality & Grades

• Grade: BioReagent — intended for laboratory research applications requiring consistent composition and low bioburden/contaminants compatible with biochemical assays. BioReagent-grade buffers are commonly used for enzyme work, protein handling, and general life-science workflows.
• ChP designation: The product name includes “(ChP)”. In general usage, ChP refers to the Chinese Pharmacopoeia. For this specific item, explicit monograph conformity, test methods, and limits are Not specified for this item; refer to CoA/Spec Sheet. Users requiring pharmacopeial compliance should confirm lot-specific certification.
• Purity profile and contaminants: Not specified for this item; refer to CoA/Spec Sheet (e.g., heavy metals, microbial limits, UV absorbance background).
• Stabilizers/antimicrobials: Not specified for this item; refer to CoA/Spec Sheet. Many dehydrated buffers are stabilizer-free and rely on dry storage for shelf stability.
• What this means in practice:
  • Expect reproducible pH on dissolution (within the product-specific tolerance) using purified water and proper temperature equilibration.
  • Suitable for routine biochemistry, protein/nucleic-acid workflows, chromatography equilibration/wash buffers, and general lab use.
  • For highly sensitive analytical applications (e.g., trace metal analysis, LC-UV at low wavelengths), consult CoA for UV background and elemental profiles.

Reaction & Applications

• Biochemical applications (general):
  • Protein handling: Dilutions, dialysis, column equilibration/wash for affinity and ion-exchange (when compatible with phosphate).
  • Enzyme assays: Many enzymes function well in phosphate near neutrality; verify for metal-dependent systems where phosphate may chelate or precipitate with cofactors.
  • Nucleic acids: DNA/RNA resuspension, storage, and electrophoresis buffers (with appropriate ionic strength and additives).
  • Immunoassays: Common as a wash or dilution buffer base (often with NaCl, Tween 20, and protein stabilizers like BSA; additives not included unless specified).
• Analytical applications:
  • UV/Vis spectroscopy: Low background above ~210–220 nm (literature), good for protein A280 monitoring and general absorbance assays.
  • Chromatography: As an aqueous phase for HIC, IEX, and SEC (mind salt strength and precipitation with organic modifiers or divalent cations).
• Practical tips (general):
  • Reconstitute with high-purity water (≥18 MΩ·cm). Mix thoroughly and allow to reach the intended measurement temperature before pH verification; adjust only if protocol allows.
  • Filter sterilize (0.22 µm) for cell-free sterile applications; avoid heat sterilization if composition is not validated for autoclaving.
  • For metal-enzyme systems, consider adding chelator-free alternatives or switching buffers to avoid phosphate inhibition/precipitation.

Reaction Conditions

The following are general, literature-based ranges for conducting work in phosphate buffer near pH 7.6; adjust per your protocol. Item-specific concentrations and limits are not provided.

• Concentration (literature/general): 10–100 mM for many biochemical assays; lower (1–10 mM) for sensitive metal-dependent enzymes to reduce phosphate interactions.
• Temperature: Commonly 4–37 °C for biomolecular applications. Phosphate buffer exhibits modest pH drift with temperature; equilibrate before measuring pH.
• Ionic strength: May be augmented with NaCl (e.g., 50–150 mM) to stabilize proteins and reduce nonspecific interactions; ensure solubility in the presence of other salts or cosolvents.
• Divalent cations: Keep Ca²⁺/Mg²⁺ below precipitation thresholds or substitute with non-precipitating buffers (HEPES/Tris) when millimolar divalent ions are required.
• Sterility: Filter sterilize through 0.22 µm membranes for sterile applications; avoid autoclaving unless validated for this specific formulation (not specified).
• Typical outcomes: Stable pH near neutrality with low UV background, suitable for absorbance/fluorescence assays and protein handling. Verify enzyme activity because phosphate may inhibit or alter some systems.

Safety & Handling

• GHS classification, signal word, hazard statements, pictograms: Not specified for this item; refer to SDS for authoritative safety information.
• General hazard profile (general knowledge): Inorganic phosphate buffers are typically of low acute toxicity but can cause eye/skin irritation as solids or concentrated solutions. Dust may be irritating to the respiratory tract.
• Personal protective equipment: Laboratory coat, suitable gloves (e.g., nitrile), and safety glasses. Avoid dust generation; handle in a well-ventilated area.
• Incompatibilities (general): Avoid mixing concentrated phosphate with solutions rich in divalent cations (Ca²⁺, Mg²⁺, Ba²⁺), which can precipitate as phosphates. Strong acids/bases will change pH and buffer capacity. Avoid contact with aluminum or zinc in wet conditions due to salt corrosion.
• First aid (overview; consult SDS):
  • Inhalation of dust: Move to fresh air; seek medical advice if symptoms persist.
  • Skin/eye contact: Rinse with water for several minutes; remove contact lenses; seek evaluation if irritation continues.
  • Ingestion: Rinse mouth with water; do not induce vomiting; seek medical attention if unwell.
• Safe handling practices: Use clean, dry utensils to prevent caking/contamination. When reconstituting, add powder to water with stirring to avoid clumping; control temperature to minimize pH drift.
• Waste considerations: Phosphate-containing aqueous waste may contribute to eutrophication; dispose per institutional and local regulations.

Solvent Selection

This product is itself a buffer system (aqueous), not a solvent to be chosen for solvation of organics. Selection considerations therefore focus on buffer suitability for the intended biochemical context.

• Polarity/miscibility (general): The reconstituted buffer is fully aqueous and miscible with water; miscibility with water-miscible co-solvents (e.g., methanol, ethanol, DMSO) is high but co-solvents will alter pH activity and may affect biological systems.
• Why choose phosphate at pH 7.6:
  • Near-physiological pH with strong buffering capacity around neutrality (pKa2 ≈ 7.20).
  • Low UV background over typical analytical wavelengths (>210–220 nm) relative to organic buffers.
  • Inorganic, non-volatile; stable over a broad temperature range.
• When to consider alternatives:
  • Systems requiring compatibility with divalent cations at millimolar levels (risk of Ca²⁺/Mg²⁺ phosphate precipitation) — consider HEPES, MOPS, or Tris.
  • Enzymes or reactions sensitive to phosphate coordination/inhibition (e.g., some kinases, phosphatases, metal enzymes) — consider Good’s buffers (HEPES, PIPES) or bicarbonate/CO2 systems.
• Comparison snapshot (general):
  • Phosphate (pH 7.6): Inorganic, strong buffering near neutral, can precipitate with Ca²⁺/Mg²⁺.
  • Tris (pKa ~8.1): Good near pH 7.6–8.5, temperature-sensitive pH, amine may participate in reactions.
  • HEPES (pKa ~7.5): Minimal metal binding, low temperature coefficient, higher cost.

Storage & Reconstitution

• Storage conditions (as sold): Room temperature (per Product Data). Keep tightly closed in a dry place to prevent moisture uptake and caking. Protect from contamination.
• Shipping: Shipped at ambient temperature (Normal) per Product Data.
• Shelf life/expiry: Not specified for this item; refer to CoA/Spec Sheet and product label.
• Reconstitution (general guidance): Dissolve the entire contents in the specified volume of purified water as indicated on the product label to obtain pH 7.6 buffer. Mix thoroughly and verify pH at the measurement temperature.
• Post-reconstitution storage (general practice, not item-specific): Store aqueous buffer at 2–8 °C for short-term use. For extended storage, prepare smaller aliquots and maintain aseptic technique or sterile filter into sterile containers. Discard if turbidity, precipitation, or microbial growth appears.
• Freeze–thaw: Generally unnecessary for simple salt buffers and may lead to container stress or concentration changes due to ice fractionation; prepare fresh as needed.
• Compatibility notes: Avoid prolonged contact with reactive metals in solution. If sterility is critical, use aseptic preparation, sterile containers, and 0.22 µm filtration.
• Documentation: Record lot number, preparation date, water source, final volume, and measured pH for traceability.

Structure & Identity

This product is a dehydrated, ready-to-reconstitute phosphate buffer blend formulated to yield an aqueous phosphate buffer at pH 7.6.

• Item-specific identifiers:
  • Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
  • CAS, InChIKey, SMILES, CID: Not applicable to this blended dehydrated buffer; not specified for this item.
• Composition note (general/literature): Dehydrated phosphate buffers are typically prepared from mixtures of inorganic phosphate salts (e.g., monosodium phosphate and disodium phosphate, or corresponding potassium salts). Exact salt identity and ratios determine final pH/ionic strength and are lot/formulation specific.
• Structural features (general knowledge): Upon dissolution, the buffering species are inorganic phosphate anions across the H2PO4−/HPO4²− conjugate acid–base pair that controls buffering near neutral pH. At pH 7.6, the mixture is enriched in HPO4²− relative to H2PO4−.
• Physical form: Dehydrated solid blend intended for dissolution in water to the labeled volume/concentration (item-specific mass-per-volume not provided).

Synthetic Utility

While primarily a life-science buffer, phosphate at pH 7.6 can be a useful aqueous medium for select chemical and bioconjugation reactions.

• Aqueous reaction medium (general): Suitable for reactions requiring neutral pH, including certain enzyme-catalyzed steps, protein crosslinking (e.g., glutaraldehyde-based conjugations often use phosphate buffers), and immobilization chemistries.
• Coordination/competition effects: Phosphate can coordinate metal centers and compete in reactions involving metal ions; it may inhibit or alter rates for metal-catalyzed processes. Avoid for reactions needing free Ca²⁺/Mg²⁺ in solution due to precipitation.
• Nucleophile/basicity: At pH 7.6, the buffer provides limited basicity and nucleophilicity; it generally does not participate in side reactions with most biomolecules, in contrast to primary amine buffers (e.g., Tris) that can react with activated esters.
• Electrophile compatibility (general): NHS-ester labeling is often performed in phosphate or bicarbonate buffers; however, phosphate concentration and pH should be controlled to balance hydrolysis and reaction rates.
• Retrosynthetic value: As an inorganic buffer, phosphate provides controlled pH without introducing UV-absorbing organics, advantageous for monitoring reactions by UV/Vis.

Target Specificity

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