Potassium Chloride Saturated Solution - BioReagent, Suitable for molecular biology, Suitable for Analysis , CAS No.7447-40-7

CAS: 7447-40-7 Cat. No.: P1528867 Formule: KCl Poids moléculaire: 74.55 Numéro CE: 231-211-8

GRADE & PURITY BioReagent, Suitable for Analysis, Suitable for molecular biology

Storage

Room temperature

Shipped In

Normal

Application

1038,1053

Vue d’ensemble

Potassium Chloride Saturated Solution is a commonly used inorganic reagent in laboratories, prepared by dissolving potassium chloride (KCl, CAS: 7447-40-7, molecular weight: 74.55) in deionized water. Store at room temperature in a sealed container. This product is a near-saturated aqueous solution. When the temperature decreases, white potassium chloride crystals may precipitate at the bottom of the container — this is a normal physical phenomenon and does not indicate product deterioration. The solution can be restored to normal use by warming to room temperature and mixing thoroughly until fully dissolved. This does not affect performance. Do not freeze, as low temperatures will exacerbate crystallization.

Major Applications

Analytical Chemistry: Serves as a filling solution for reference electrodes (calomel electrodes and silver-silver chloride electrodes), suitable for potentiometric analysis and electrochemical measurement systems.

Molecular Biology: Used for nucleic acid precipitation and salting-out experiments.

Physicochemical Experiments: Employed in the preparation of high ionic strength systems, colloid experiments, ionic strength adjustment, and certain salting-out separation procedures. 

Procedure (for reference only):

Operate according to the specific requirements of the experiment.

Precautions:

1.Please use the reagent as soon as possible after opening toavoid affecting subsequent experimental results.

2.For your safety and health, please wear a lab coat and disposable gloves during operation.

3.This product is for research use only. Strictly prohibited for any other use.

Specifications

Spécifications et pureté

BioReagent, Suitable for molecular biology, Suitable for Analysis

Stabilité et stockage

Store at Room temperature long term (12 months).

Conditions de stockage de stockage

Room temperature

Expédié en

Normal

Grade

BioReagent, Suitable for Analysis, Suitable for molecular biology

Product Line

Produits biologiques

Noms et identifiants

Isomères SMILES

[Cl-].[K+]

WGK Allemagne

1

Poids moléculaire

74.55

Propriétés chimiques et physiques

• Point d'ébullition (°C): 1413 °C/1013 hPa
• Point de fusion (°C): 770 °C (lit.)

Application Protocols

No vendor-verified protocols are provided for this item. Typical research uses (literature/general) include:

• Reference electrode maintenance: Fill Ag/AgCl reference electrodes and junctions with saturated KCl; filter solution (0.2 µm) before use; ensure no air bubbles remain. Replace periodically to maintain stable potentials.
• Ionic strength adjustment: Prepare working solutions by diluting the saturated stock to the desired molarity (e.g., 0.1–3 M) using volumetric techniques; confirm concentration by conductivity or gravimetry if needed.
• Salting-out: Add saturated KCl dropwise to aqueous mixtures while stirring; monitor turbidity/phase separation; maintain constant temperature to avoid re-dissolution/crystallization cycles.

For step-by-step, validated procedures, consult your lab’s SOPs or primary literature. Refer to the product CoA/Spec Sheet for any lot-specific instructions.

Biological Roles

• General biochemistry (literature):

  • Potassium (K+) is the principal intracellular cation in most cells, critically influencing membrane potential, osmotic balance, and enzyme activation. Chloride (Cl−) is a major anion participating in charge neutrality, acid–base balance, and transport processes through channels and co-transporters.
  • High external KCl can depolarize excitable cells (research contexts), modulate channel activity, and affect protein stability via Hofmeister effects. Such uses typically employ defined molarities rather than truly saturated solutions; select concentrations appropriate to the system.

• Protein/nucleic acid interactions:

  • Ionic strength modulates electrostatic screening, binding affinities, folding equilibria, and phase behavior of biomacromolecules. K+ often stabilizes certain nucleic acid secondary structures (e.g., G-quadruplexes) more effectively than Na+.

• Enzymology:

  • Many enzymes are sensitive to specific cations/anions; K+ may be required for optimal activity in some polymerases and kinases, whereas high Cl− can inhibit or alter activity of others. Empirical optimization is recommended.

Note: The product is BioReagent grade and for research use only. It is not intended for clinical/therapeutic applications. For cell culture or organism exposure, verify endotoxin/bioburden and exact concentration on the CoA and adjust to the target molarity rather than using a saturated solution directly.

Buffer Applications

A saturated KCl solution is not itself a buffering system (no conjugate acid/base pair). However, KCl is routinely included in buffer formulations to adjust ionic strength and conductivity.

• Common research uses (literature/general):

  • Addition to Tris, HEPES, or phosphate buffers at defined concentrations (e.g., 50–500 mM) to modulate protein–nucleic acid interactions and chromatographic binding/wash conditions.
  • Preparation of saline-like solutions (e.g., PBS variants) where partial substitution of NaCl with KCl provides physiological K+ levels (these applications typically use low-millimolar KCl, not saturated solutions).
  • ISAB for potentiometry: Fixed ionic strength background using concentrated KCl for ion-selective electrodes.

• Practical guidance:

  • If starting from this saturated stock, prepare working solutions by volumetric dilution to the desired molarity; verify final ionic strength and pH after dilution.
  • Temperature affects saturation; ensure crystals are fully dissolved before making volumetric dilutions.

Exact pH, conductivity, and concentration for this item are not specified; refer to the CoA for precise formulation details of the supplied saturated solution.

Green Alternatives

This product is already an aqueous inorganic salt solution with low environmental/health burden relative to many organic reagents. “Greenness” considerations mainly involve waste minimization and chloride management.

• Environmental aspects (general):

  • Water as solvent; nonflammable; low volatility; low acute toxicity (relative to organic solvents). Main concern is chloride load in wastewater and potential corrosion of infrastructure.

• Alternatives/comparisons (literature):

  • Saturated KCl vs 3 M KCl for electrodes: Lower concentration reduces chloride discharge and salt consumption while often providing adequate reference stability; trade-off is slightly greater junction potential variability.
  • KCl vs NaCl brines: Sodium chloride brines have broadly similar environmental profiles; selection may depend on ion-specific biological effects or equipment compatibility.
  • Non-chloride electrolytes (e.g., KNO3) for junctions: Reduce chloride-specific corrosion or interference but may be less compatible with Ag/AgCl references.

• Practical green tips:

  • Prepare only the volume needed; store sealed to avoid evaporation and recrystallization cycles.
  • Reuse/refresh electrode filling solutions by filtering rather than discarding when slight turbidity forms (if acceptable for your protocol).
  • Segregate chloride-rich aqueous waste and neutralize/ dilute per institutional guidelines.

Pharmaceutical Uses

This product is designated BioReagent grade and is for research use only. It is not offered as a USP/EP or clinical grade material.

• General formulation roles of KCl solutions (literature/context, not specific to this item):

  • Isotonicity/osmolality adjustment in aqueous formulations.
  • Chloride source for controlling ionic strength in process buffers and cleaning solutions.
  • Electrolyte in pH and reference electrode maintenance within pharmaceutical QC labs.

• Compliance and documentation:

  • For GMP or clinical manufacturing, specifications (e.g., trace metals, bioburden, endotoxin, particulates) and pharmacopeial monographs would be required; these are not specified for this item. Verify suitability via CoA/Spec Sheet and internal qualification if using in regulated environments.

• Handling considerations:

  • Use corrosion-resistant materials in systems exposed to chloride-rich solutions.
  • Avoid cross-contamination with drug product areas unless controlled under appropriate QA procedures.

Physical Properties

• Item-specific properties (as supplied):

  • Concentration of KCl: Not specified for this item; refer to CoA/Spec Sheet.
  • Density (solution): Not specified for this item; refer to CoA/Spec Sheet.
  • pH: Not specified for this item; refer to CoA/Spec Sheet.
  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.

• Literature/general values for potassium chloride and its saturated solutions (for context; actual lot values may differ):

  • Solubility of KCl in water (literature): ~34 g KCl per 100 g H2O at 20 °C; ~36 g/100 g at 25 °C; ~56–57 g/100 g at 100 °C. Saturation therefore increases appreciably with temperature.
  • Approximate molarity of saturated KCl (literature): ~4.0–4.5 M at 20–25 °C (depends on temperature and precise density/volume expansion of the solution).
  • Density of saturated KCl solution (literature): commonly around 1.18–1.20 g/mL at ~20–25 °C (varies with exact concentration and temperature).
  • Electrolyte properties: high ionic strength, high conductivity; dielectric behavior dominated by water.
  • Pure KCl (solid, literature): MP ~770 °C; BP (decomposes) >1400 °C; these are not directly relevant to the aqueous solution but characterize the solute.

Important: Use the product CoA for exact concentration, density, and pH of the supplied saturated solution; literature values are provided for planning only.

Quality and Grades

• Supplied grade: BioReagent (item-specific). This generally denotes suitability for common biological research workflows (e.g., buffer preparation, electrophysiology media, ionic strength adjustments) with attention to background contaminants that could interfere with biochemical assays.

• What BioReagent typically implies (general guidance):

  • Controlled levels of common impurities (organics, metals, particulates) appropriate for research use in biology/biochemistry.
  • May be filtered/clarified; bioburden typically managed for lab use (not sterile unless stated). Exact impurity limits are not specified for this item; refer to CoA/Spec Sheet.

• Not a clinical/therapeutic grade: This product is for research use only (as stated). It is not manufactured to USP/EP or injection-grade specifications unless explicitly noted.

• Stabilizers/Preservatives: Not specified for this item; refer to CoA/Spec Sheet. If sterility or preservative-free status is critical, verify by lot documentation.

• UV/LC suitability: If using in chromatography/electrochemistry, check the CoA for conductivity, pH, and trace metal background; no specific low-UV or LC/MS claims are made in this listing.

Reaction and Applications

• Electrochemistry (literature):

  • Standard filling/electrolyte for Ag/AgCl reference electrodes uses saturated KCl to maintain constant chloride activity and minimize junction potentials. Pre-saturated KCl in the salt bridge reduces drift.

• Analytical chemistry:

  • Ionic strength adjustment buffer (ISAB) in ion-selective electrode (ISE) measurements to fix activity coefficients.
  • Precipitation reactions: Provides Cl− to precipitate Ag+ as AgCl (qualitative and quantitative argentometric analyses; Mohr method employs KCl/NaCl as standards).

• Biochemistry and separations:

  • Salting-out: High ionic strength promotes protein precipitation and phase separation (e.g., aqueous two-phase polymer systems) via Hofmeister effects; K+ and Cl− have characteristic positions in the Hofmeister series.
  • Nucleic acid workflows: Chloride salts can influence DNA/RNA precipitation and binding equilibria (often used at defined molarities rather than saturated; choose concentration appropriately).

• Synthetic chemistry:

  • Common-ion/phase behavior: Adding concentrated KCl can drive extraction partitioning (salting-out organics from water) and adjust ionic strength to influence reaction rates of ionic processes.
  • Halide source: Provides chloride in substitution/complexation equilibria in aqueous media; can shift equilibria for metal–ligand chloride complexes.

Practical tips (general):

• Use solutions pre-equilibrated at experimental temperature; KCl solubility is temperature dependent, and crystals may form or redissolve with temperature changes.
• Filter through 0.2 µm if particulate-free electrolyte is required for electrochemical cells.

Reaction Conditions

General guidance (literature) for using saturated KCl as an aqueous electrolyte or reagent; actual conditions depend on the specific chemistry or analytical setup.

• Electrochemistry:

  • Reference electrode filling: Use saturated KCl at the instrument’s operating temperature; ensure the salt bridge is pre-saturated to minimize junction potentials. Replace/refresh if crystals obstruct the frit. Typical alternatives are 3 M KCl when saturation is not required.

• Precipitation/argentometry:

  • For quantitative AgCl precipitation, maintain chloride in measurable excess and stir vigorously; the presence of saturated KCl ensures rapid nucleation and growth. Filter through fine porosity for gravimetry.

• Salting-out and partitioning:

  • Add saturated KCl incrementally to aqueous mixtures to reach target ionic strength. Monitor for phase separation in aqueous two-phase systems or decreased solubility of hydrophobes. Temperature control is important as KCl solubility is temperature dependent.

• Concentration references (approximate, literature):

  • Saturated KCl at ~20–25 °C corresponds to roughly 4.0–4.5 M chloride; density typically ~1.18–1.20 g/mL. Verify with CoA or determine empirically by gravimetry if exact molarity is critical.

• Materials and compatibility:

  • Use glass or corrosion-resistant polymers (PP, PE, PTFE). Avoid prolonged contact with susceptible metals due to chloride-induced corrosion.

These conditions are general references; tailor to your protocol, and consult primary literature or validated SOPs for method-specific parameters.

Safety and Handling

• GHS/Classification (item-specific): Not specified for this item; refer to SDS for authoritative hazard information.

• General safety profile (literature/context): Aqueous KCl solutions are generally considered low hazard for laboratory use but can cause eye/skin irritation on contact and may be harmful if ingested in significant quantity. Always apply prudent laboratory hygiene.

• Recommended PPE and practices:

  • Wear safety glasses/goggles, lab coat, and appropriate gloves (e.g., nitrile) when handling.
  • Avoid aerosol generation; do not ingest; avoid contact with eyes and prolonged skin exposure.
  • Wash thoroughly after handling; keep food/drink out of lab areas.

• First-aid (overview; defer to SDS):

  • Eyes: Rinse cautiously with water for several minutes; remove contact lenses if present and easy to do; seek medical advice if irritation persists.
  • Skin: Wash with soap and water; remove contaminated clothing.
  • Ingestion: Rinse mouth; seek medical attention if large quantity ingested or if symptoms occur.
  • Inhalation: Unlikely for liquid; move to fresh air if aerosol/mist is inhaled.

• Chemical incompatibilities/precautions (literature):

  • Avoid mixing with concentrated acids/bases that can alter pH significantly for your process; avoid contact with silver salts (e.g., AgNO3) if precipitation of AgCl is problematic.
  • Corrosion: Chloride-containing solutions can be corrosive to certain stainless steels over time; use compatible materials (glass, certain polymers) for storage/transfer.

Always consult the product SDS for definitive hazard, handling, and disposal guidance.

Solvent Selection

This product is an aqueous saturated electrolyte solution, not an organic solvent. Selection considerations focus on ionic strength, conductivity, and compatibility rather than solvation power.

• Polarity/miscibility (general):

  • Fully water-based; miscible with water. Mixing with organic solvents (e.g., alcohols) reduces KCl solubility and can cause salting-out or precipitation.
  • High ionic strength markedly increases solution conductivity and affects activity coefficients.

• When to choose saturated KCl vs alternatives:

  • Electrochemistry: Saturated KCl is a standard filling solution for reference electrodes (Ag/AgCl), offering stable chloride activity and junction potential control.
  • Ionic strength control: Use where maximal, reproducible chloride ionic strength is required (e.g., protein precipitation/salting-out studies, phase partitioning experiments).
  • Alternative salts: NaCl solutions provide similar ionic strength with different cation interactions; for lower chloride activity requirements, use defined molarity KCl (e.g., 0.1–1.0 M).

• Compatibility:

  • Glass, HDPE, PP, PTFE are typically compatible. Avoid prolonged contact with metals prone to chloride-induced corrosion.

• Small comparison (literature, qualitative):

  • Saturated KCl: very high ionic strength; optimal for Ag/AgCl reference electrodes.
  • 3 M KCl: common for electrochemistry where reduced chloride activity is desired.
  • NaCl brine: similar ionic strength effects but different ion-specific interactions; may impact biomacromolecules differently than K+.

Storage and Reconstitution

• Storage (item-specific): Room temperature (as provided). Shipments occur under normal ambient conditions.

• Stability and handling (general):

  • Keep tightly closed to minimize evaporation; evaporation can increase concentration and induce crystallization of KCl.
  • If crystals form upon cooling or evaporation, redissolve by warming to ~30–40 °C with stirring, then allow to re-equilibrate at the intended use temperature before use.
  • Avoid contamination; if particulate-sensitive applications (e.g., electrochemistry), filter through 0.2 µm PTFE or PES membrane prior to use.

• Reconstitution: Not applicable; product is supplied as a ready-to-use solution. For specific working concentrations, prepare dilutions with high-purity water (e.g., 18 MΩ·cm) using volumetric glassware.

• Container/materials: Store in compatible containers (glass, HDPE, PP). Avoid metal fittings prone to chloride-induced corrosion.

• Shelf life: Not specified for this item; refer to CoA/Spec Sheet. Inspect periodically for microbial growth or turbidity; if sterility is required, sterile-filter immediately prior to use.

• Research Use Note: For research use only.

Structure and Identity

Aqueous saturated solution of potassium chloride (KCl); the solute is an inorganic alkali metal halide present as fully dissociated K+ and Cl− in water.

• Item-specific identifiers (this listing):

  • CAS: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES / InChIKey: Not specified for this item; refer to CoA/Spec Sheet.

• Literature identifiers for the solute (potassium chloride):

  • Molecular formula (literature): KCl
  • Molecular weight (literature): 74.55 g/mol
  • SMILES (literature): [K+].[Cl-]
  • InChIKey (literature): OYBQJKUFHFZGSL-UHFFFAOYSA-M
  • CAS (literature): 7447-40-7

• Structural features (descriptive, literature):

  • In aqueous media, KCl exists as solvated ions: K+ (spherically symmetric cation) and Cl− (spherically symmetric anion), both strongly hydrated by water.
  • No stereocenters or covalent functional groups; purely ionic character.
  • 2D depiction would show dissociated ions with hydration shells rather than a discrete covalent molecule.

Note: The product is a prepared saturated aqueous solution; exact concentration and identifiers for the solution matrix are not specified for this item and should be confirmed on the product CoA/Spec Sheet.

Synthetic Utility

• Ionic strength and activity control (literature): Concentrated KCl is a convenient way to increase ionic strength in aqueous-phase reactions, influencing rates of SN1/SN2 processes, ion-exchange equilibria, and catalytic cycles sensitive to electrolyte effects.

• Halide source/ligand exchange:

  • Provides chloride to shift equilibria in coordination chemistry (e.g., converting aquo complexes to chloro complexes of transition metals in water).
  • Useful in argentometric standardizations and in setting chloride background for redox couples containing metal halides.

• Phase behavior and separations:

  • Salting-out: High KCl concentrations reduce the solubility of many organics in water and can promote phase separation in aqueous biphasic systems (e.g., polymer–salt systems for extraction and bioprocessing).

• Workup utility:

  • “Brine” washes are commonly NaCl; however, KCl brine can be employed when sodium contamination is undesirable or when K+ exerts favorable ion-pairing effects.

• Practical notes:

  • Prepare temperature-equilibrated saturated KCl to avoid undissolved solids during dosing. If crystals persist, gently warm and stir to fully saturate, then cool to the target working temperature and decant/filtrate.
  • For precise chloride activity control, use saturated KCl at the experiment temperature or switch to a defined molarity (e.g., 0.5–3 M) prepared gravimetrically.

Target Specificity

Not applicable. This product is an inorganic salt solution, not a biological affinity reagent or antibody. No antigen/epitope specificity, species reactivity, clone, or isotype information applies.