Bacteriostatic Water 50ml is a sterile, non-pyrogenic solution of USP-grade water containing 0.9% (9 mg/mL) benzyl alcohol, engineered for the reconstitution and analytical preservation of lyophilized research compounds. In laboratory environments, this specialized diluent prevents bacterial cell proliferation within reconstituted vials, allowing researchers to draw repeated samples for in vitro assays without compromising solution sterility. PX1 Research provides analytical-grade reconstitution media validated by lot-specific certificates of analysis and manufactured in US-based GMP-compliant facilities.
Bacteriostatic Water 50ml is a sterile, non-pyrogenic solution of USP-grade water containing 0.9% (9 mg/mL) benzyl alcohol, engineered for the reconstitution and analytical preservation of lyophilized research compounds. In laboratory environments, this specialized diluent prevents bacterial cell proliferation within reconstituted vials, allowing researchers to draw repeated samples for in vitro assays without compromising solution sterility. PX1 Research provides analytical-grade reconstitution media validated by lot-specific certificates of analysis and manufactured in US-based GMP-compliant facilities.
Bacteriostatic Water 50ml serves as a critical reagent in biochemistry, pharmacology, and cellular biology laboratories requiring multi-use liquid media for dry powder compounds. Formulated with high-purity USP water and preserved with 0.9% (w/v) benzyl alcohol, this diluent exhibits a neutral pH range (4.5 to 7.0) and zero added buffering agents or tonicity modifiers. The inclusion of benzyl alcohol acts as a bacteriostatic agent—inhibiting the metabolic activity and replication of Gram-positive and Gram-negative bacteria, fungi, and yeasts that could otherwise contaminate multi-dose laboratory containers during routine volumetric withdrawal.
In analytical workflows, the 50ml volume format offers substantial efficiency for high-throughput screening, serial dilution series, and long-term assay protocols. Unlike single-use sterile water diluents, bacteriostatic water maintains microbial stasis after repeated septum punctures, ensuring that reconstituted peptide solutions, proteins, and molecular probes remain chemically pure and biologically uncorrupted throughout experimental execution. Laboratories utilizing bacteriostatic water 50ml gain reliable preservation without altering the underlying target mechanism of the primary research compound.
The primary functional component differentiating bacteriostatic water from standard purified water is benzyl alcohol (C7H8O, CAS 100-51-6) at a concentration of 9 mg per milliliter. Benzyl alcohol is an aromatic alcohol possessing amphiphilic properties, allowing it to penetrate and destabilize the lipid bilayer of microbial cell membranes. At the 0.9% concentration, the molecule exerts a bacteriostatic rather than a harsh bactericidal action: it disrupts membrane fluidity and inactivates membrane-bound enzyme complexes responsible for bacterial respiration and active transport, rendering microorganisms incapable of cellular division.
Preclinical microbial challenge assays demonstrate that 0.9% benzyl alcohol effectively suppresses common laboratory contaminants, including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. Because benzyl alcohol does not interact directly with most standard peptide backbones or side-chain functional groups under recommended storage conditions, it provides a stable solvent environment. Researchers conducting in vitro assays rely on this biochemical stability to eliminate background contamination from confounding experimental measurements.
Lyophilization (freeze-drying) is the gold-standard method for preserving fragile synthetic peptides, proteins, and small molecules. However, returning these solid cake matrices into aqueous solution requires a diluent that facilitates rapid, complete dissolution while protecting the primary peptide sequence from hydrolytic degradation or microbial contamination. When reconstituting compounds such as BPC-157, Semaglutide, or Tirzepatide, bacteriostatic water 50ml provides the necessary solvent shell to hydrate polar residues without introducing exogenous pyrogenicity.
The reconstitution process involves hydrophobic and ionic hydration. Water molecules assemble around the hydrophilic domains of the peptide chain, disrupting non-covalent intermolecular bonds formed during freeze-drying. The presence of 0.9% benzyl alcohol does not alter the thermodynamic solubility limit of most short- and long-chain peptides. However, researchers must ensure precise volumetric calculations to achieve target concentrations (measured in mg/mL or µg/µL) necessary for quantitative dosing in preclinical models.
Selecting the correct aqueous diluent depends entirely on the design of the experimental assay, the target storage duration, and container usage patterns. A comparative analysis of standard laboratory diluents highlights key operational differences:
Bacteriostatic Water 50ml contain 0.9% benzyl alcohol, enabling multi-puncture access over a 28-day functional lifespan while preventing microbial proliferation. Sterile Water for Injection (SWFI) lacks antimicrobial agents; once punctured, unpreserved water must be used immediately or discarded, making it unsuitable for multi-dose peptide protocols. Normal Saline (0.9% NaCl) provides isotonicity but lacks antimicrobial preservation and can induce salt-mediated aggregation or precipitation in hydrophobic peptides like CJC-1295 DAC. For comprehensive guidance on solvent selection, researchers should consult our detailed lyophilized peptide reconstitution guide.
In cell culture work, receptor binding studies, and animal model administration, bacterial endotoxins (lipopolysaccharides, or LPS) represent a critical confounding variable. Endotoxins originating from Gram-negative bacterial cell walls can trigger non-specific inflammatory signaling, alter cytokine profiles, and invalidate experimental readouts in preclinical research. Therefore, reconstitution media must meet strict endotoxin thresholds in addition to sterility requirements.
PX1 Research ensures that every lot of bacteriostatic water 50ml is evaluated using standard Limulus Amebocyte Lysate (LAL) testing protocols, verifying endotoxin levels remain below 0.25 EU/mL. Furthermore, the 0.9% benzyl alcohol content actively prevents secondary microbial growth that could synthesize post-production endotoxins within open multi-use vials. Laboratories purchasing through our wholesale lab portal receive full batch documentation confirming compliance with rigorous purity and pyrogenicity criteria.
Achieving reproducible analytical results requires standardized handling procedures when introducing bacteriostatic water into lyophilized compound vials. Below is the recommended benchtop protocol for laboratory investigators:
1. Disinfect the rubber septum of both the bacteriostatic water 50ml container and the target peptide vial using 70% isopropyl alcohol, allowing them to air dry completely. 2. Using a sterile, single-use laboratory syringe, draw the exact volume of bacteriostatic water required based on desired stock concentration calculations. 3. Insert the needle at a 45-degree angle through the peptide vial septum, directing the stream of diluent down the glass interior wall rather than directly onto the lyophilized powder cake. 4. Gently swirl the vial in a circular horizontal motion until complete dissolution occurs. Never agitate, shake, or vortex fragile peptide solutions, as mechanical shear stress can cause protein denaturation or irreversible aggregation. 5. Mark the vial with reconstitution date, final concentration, and store under appropriate thermal conditions as detailed in our peptide storage guide.
While bacteriostatic water 50ml is the universal diluent for the vast majority of hydrophilic and moderately hydrophobic research peptides, certain highly hydrophobic sequences or large complex proteins may present unique dissolution challenges. Peptides containing high proportions of non-polar amino acid residues (such as leucine, isoleucine, valine, and phenylalanine) may require initial solvation in a minimal volume of dimethyl sulfoxide (DMSO) or dilute acetic acid prior to final dilution with bacteriostatic water.
In vitro studies demonstrate that introducing benzyl alcohol in a 0.9% concentration does not interfere with mass spectrometry analysis, high-performance liquid chromatography (HPLC) peak retention times, or Western blot assays, provided baseline control blanks are incorporated into the experimental design. For all standard research sequences, including GHRPs, GHRHs, metabolic modulators, and signal peptides, bacteriostatic water remains the preferred vehicle for stable solution prep.
The physical integrity of bacteriostatic water 50ml relies on proper storage conditions both before and after container entry. Unopened vials should be stored at controlled room temperature (20°C to 25°C / 68°F to 77°F) away from direct sunlight and ultraviolet sources. Benzyl alcohol can undergo slow photo-oxidation if exposed to intense light over prolonged periods, potentially generating trace benzaldehyde impurities.
Once punctured, the 50ml vial should be kept in a clean laboratory refrigerator at 2°C to 8°C (36°F to 46°F) and utilized within 28 days. Freezing bacteriostatic water is strictly not recommended: freezing causes ice crystal formation that alters local benzyl alcohol concentrations and can compromise the mechanical integrity of glass vial walls or rubber septa seals. Researchers managing large compound libraries can browse our complete line of research peptides for compatible diluent specifications.
In scientific research, sample purity and supplier transparency directly impact data integrity and experiment reproducibility. Substandard or unverified diluents may introduce heavy metals, organic impurities, or bacterial contamination into sensitive assay systems. PX1 Research adheres to stringent quality assurance protocols to ensure every 50ml vial of bacteriostatic water meets analytical standards.
Our diluents are manufactured in US-based, GMP-compliant facilities under ISO 9001 and ISO 17025 quality management systems. Every production lot undergoes independent, third-party laboratory verification, including Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) for purity, Mass Spectrometry (MS) for identity, microbial limits testing, and LAL endotoxin quantification. Lot-specific Certificates of Analysis (COAs) are accessible for every order, guaranteeing batch traceability and complete peace of mind for lab managers.
Securing high-purity, fully validated reconstitution media is fundamental to maintaining control across preclinical research workflows. PX1 Research specializes in supplying US-manufactured research chemicals, peptides, and laboratory diluents tailored to academic, pharmaceutical, and private research institutions.
Orders placed with PX1 Research ship directly from our centralized distribution facilities located in California and Arizona, featuring same-day dispatch for orders confirmed Monday through Friday before 12:00 PM PST. Every product is backed by lot-specific analytical reporting, secure packaging, and dedicated technical support to support your laboratory's ongoing experimental objectives.
What is the exact chemical composition of Bacteriostatic Water 50ml?
Bacteriostatic Water 50ml consists of high-purity, non-pyrogenic sterile water for injection containing 0.9% (9 mg/mL) benzyl alcohol as an antimicrobial preservative. It contains no added buffers or tonicity agents and has a pH range of 4.5 to 7.0.
Why is 0.9% benzyl alcohol added to bacteriostatic water?
Benzyl alcohol functions as a bacteriostatic preservative by disrupting bacterial cell membrane permeability and inhibiting cellular division. This prevents microbial contamination during repeated multi-dose access in laboratory settings.
How long is a 50ml vial of bacteriostatic water usable after initial puncture?
Once the rubber septum is punctured, the vial maintains verified antimicrobial preservation for up to 28 days when stored at refrigerated temperatures (2°C to 8°C) in a clean laboratory environment.
Can bacteriostatic water 50ml be frozen for storage?
No. Freezing bacteriostatic water is not recommended as phase separation can alter benzyl alcohol concentration and cause structural stress or micro-cracks in the glass vial and septum seal.
What is the endotoxin limit for PX1 Research bacteriostatic water?
Every lot of PX1 Research bacteriostatic water is tested via LAL assay to verify endotoxin levels remain below 0.25 EU/mL, ensuring compatibility with sensitive in vitro assays and cell culture models.
How does bacteriostatic water differ from sterile water for injection?
Sterile Water for Injection (SWFI) contains no antimicrobial preservatives and must be used immediately upon opening. Bacteriostatic water contains 0.9% benzyl alcohol, allowing multiple sampling entries over 28 days.
Is bacteriostatic water suitable for all research peptides?
Bacteriostatic water is compatible with the vast majority of synthetic research peptides. Highly hydrophobic peptides may require initial solvation in a minimal volume of organic solvent (such as DMSO) before final dilution with bacteriostatic water.
Where is PX1 Research bacteriostatic water manufactured and shipped from?
PX1 Research diluents are manufactured in US-based GMP-compliant facilities and shipped directly from our warehouse hubs in California and Arizona with same-day shipping on weekday orders placed before cutoff.
All products are sold strictly for laboratory and research use only. Not for human or veterinary use, diagnosis, treatment or consumption. Statements have not been evaluated by the FDA.