Research-grade 5ml bacteriostatic water serves as a critical diluent for reconstituting lyophilized compounds in laboratory settings. Formulated with 0.9% benzyl alcohol in sterile, non-pyrogenic water, it provides a stable environment that inhibits bacterial contamination during multi-dose benchwork.
Research-grade 5ml bacteriostatic water serves as a critical diluent for reconstituting lyophilized compounds in laboratory settings. Formulated with 0.9% benzyl alcohol in sterile, non-pyrogenic water, it provides a stable environment that inhibits bacterial contamination during multi-dose benchwork.
5ml bacteriostatic water is a sterile, non-pyrogenic preparation of water for injection containing 0.9% (9 mg/mL) benzyl alcohol added as a bacteriostatic preservative. It is specifically prepared for laboratory research use to reconstitute lyophilized peptides, proteins, and chemical reagents in multi-dose experimental workflows. The included 0.9% benzyl alcohol content suppresses the growth of Gram-positive and Gram-negative bacteria, facilitating safe repeated sampling over an extended bench period without compromising solution integrity.
In cell culture preparation, biochemical assays, and preclinical animal models, maintaining liquid reagent stability is paramount. Standard sterile water lacks antimicrobial agents, allowing opportunistic micro-organisms to propagate once the vial stopper is punctured. A 5ml unit volume of bacteriostatic water offers an optimal balance between sufficient reconstitution fluid for standard laboratory multi-vial series and minimizing excess reagent waste in controlled experimental setups.
The primary functional component distinguishing bacteriostatic water from standard sterile water for injection is benzyl alcohol ($C_7H_8O$). At a concentration of 0.9% w/v, benzyl alcohol acts as a mild hydrophobic antimicrobial agent. It partition into the lipid bilayer of microbial cell membranes, causing structural disruption, increased membrane permeability, and subsequent loss of cellular homeostasis without inducing immediate cell lysis that could contaminate assay environments with intracellular debris.
This mechanism is specifically bacteriostatic rather than bactericidal at room temperature. It prevents micro-organisms from replicating while maintaining a static population count below critical detection thresholds. In vitro testing demonstrates that maintaining 0.9% benzyl alcohol effectively prevents bacterial proliferation of common laboratory contaminants such as *Escherichia coli*, *Staphylococcus aureus*, and *Pseudomonas aeruginosa* for up to 28 days following initial container entry when stored under appropriate laboratory refrigeration.
Lyophilized research compounds are typically supplied as freeze-dried cakes to preserve their primary amino acid sequence and secondary structural stability during storage. Before introduction into enzymatic assays, receptor-binding studies, or preclinical models, these compounds must be solubilized. Using 5ml bacteriostatic water provides a consistent, analytical-grade solvent that preserves peptide integrity while ensuring uniform concentration control.
When reconstituting highly sensitive research peptides available across our all peptides directory, solvent purity directly impacts experimental reproducibility. Impurities or pH shifts in the reconstitution matrix can catalyze peptide degradation pathways such as deamidation (particularly at asparagine and glutamine residues), oxidation of methionine residues, or aggregation. Standardized 5ml bacteriostatic water maintains a physiological pH range (typically 4.5–7.0) compatible with a broad range of synthetic peptides.
Selecting the correct diluent depends heavily on the specific peptide sequence, target assay, and intended duration of use. Laboratories frequently compare bacteriostatic water against plain sterile water for injection, normal saline (0.9% NaCl), and specialized weak acid buffers like dilute acetic acid.
While standard sterile water is ideal for immediate single-use assays where benzyl alcohol might interfere with specific sensitive cell cultures, it offers zero protection against microbial contamination if stored after puncture. Conversely, normal saline provides isotonicity but lacks antimicrobial preservation and can induce aggregation in basic or hydrophobic peptides. For standard multi-use preclinical protocols involving compounds such as BPC-157 10mg, TB-500 10mg, or CJC-1295 DAC, 5ml bacteriostatic water remains the gold standard diluent due to its combination of shelf-life extension and broad chemical compatibility. Detailed preparation protocols can be reviewed in our comprehensive peptide reconstitution guide.
Hydrolysis is one of the primary degradation pathways affecting synthetic peptides in aqueous solution. Water molecules directly attack peptide bonds, leading to cleavage and loss of biological activity over time. The presence of 0.9% benzyl alcohol in 5ml bacteriostatic water alters the hydrogen-bonding network of water slightly, which in preclinical observations has been shown to reduce rate constants for temperature-dependent hydrolysis compared to unpreserved pure water.
Furthermore, maintaining precise temperature controls (2°C to 8°C) post-reconstitution significantly decelerates kinetic degradation. Preclinical assays indicate that peptides dissolved in bacteriostatic water retain structural integrity over repeated freeze-thaw cycles far better than those in unpreserved media, provided the temperature remains tightly regulated. For long-term preservation parameters of dry and solubilized cakes, consult our guide on lyophilized peptide storage protocols.
For valid scientific research, reconstitution diluents must be free of extraneous contaminants that could introduce variables into biological systems. Endotoxins—lipopolysaccharides (LPS) derived from the outer membrane of Gram-negative bacteria—are potent inflammatory mediators that can invalidate in vitro receptor binding assays and preclinical animal experiments by inducing non-specific immune activation.
PX1 Research enforces rigorous quality control standards on every lot of 5ml bacteriostatic water. Each batch undergoes stringent third-party laboratory verification, including USP <85> Bacterial Endotoxin testing (confirming levels strictly below 0.25 EU/mL) and USP <71> Sterility testing. High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS) are utilized to verify the precise 0.9% benzyl alcohol concentration and absence of chemical impurities, ensuring complete lot-to-lot consistency.
Proper aseptic technique is mandatory when reconstituting research compounds with 5ml bacteriostatic water to maintain sterility throughout the experimental lifespan:
1. **Preparation**: Clean the laminar flow hood or biosafety cabinet work surface with 70% isopropyl alcohol. Allow the rubber stoppers of both the bacteriostatic water vial and the target lyophilized peptide vial to dry after sanitizing with alcohol wipes. 2. **Volumetric Transfer**: Using a sterile laboratory syringe, draw the exact calculated volume of 5ml bacteriostatic water required for your target concentration. 3. **Diluent Introduction**: Aim the syringe needle toward the glass wall of the peptide vial rather than directly onto the lyophilized cake. Allow the water to stream down slowly to prevent shearing forces that can cause protein denaturation or excessive foaming. 4. **Solubilization**: Gently swirl the vial in a circular motion until the solute is fully dissolved. Never shake reconstituted peptide solutions aggressively. 5. **Post-Reconstitution Storage**: Mark the vial with the reconstitution date. Store the solubilized compound at 2°C to 8°C. Discard any remaining bacteriostatic water solution 28 days after initial vial puncture to ensure baseline safety and precision.
Achieving accurate molarities or mass concentrations in laboratory experiments relies on precise dilution calculations. The 5ml total volume provided in PX1 Research bacteriostatic water vials allows for flexible concentration mapping across single or multiple research vials.
For example, adding 2.0 mL of bacteriostatic water to a vial containing 10 mg of lyophilized peptide yields a final working solution concentration of 5.0 mg/mL (or 500 mcg per 0.1 mL). Adding the full 5.0 mL of diluent to a 10 mg sample yields a concentration of 2.0 mg/mL. Precision volumetric equipment and calibrated micropipettes should always be utilized when sampling reconstituted reagents for analytical testing. Browse our research hub for underlying scientific documentation on molecular weight calculations and molarity adjustments.
When procuring laboratory supplies, institutional researchers require absolute transparency, batch traceability, and reliable fulfillment. PX1 Research manufactures diluents and research compounds in state-of-the-art, GMP-compliant USA facilities, adhering strictly to ISO 17025 laboratory testing standards.
Every unit of 5ml bacteriostatic water ships directly from our California and Arizona distribution hubs with same-day dispatch for orders placed before daily cutoff times. Every single lot is accompanied by a publicly verifiable Certificate of Analysis (COA) detailing purity, pH, benzyl alcohol concentration, and endotoxin levels. Academic institutions, private laboratories, and commercial R&D facilities seeking bulk procurement or dedicated institutional accounts can access customized arrangements through our wholesale portal.
What is the concentration of benzyl alcohol in 5ml bacteriostatic water?
5ml bacteriostatic water contains exactly 0.9% (9 mg/mL) benzyl alcohol w/v dissolved in sterile, non-pyrogenic water for injection.
Why is 5ml bacteriostatic water preferred over standard sterile water for peptide reconstitution?
The 0.9% benzyl alcohol acts as a bacteriostatic preservative that prevents bacterial growth, making it suitable for multi-dose laboratory applications over a 28-day window post-puncturing. Standard sterile water lacks preservatives and must be used immediately or discarded.
What is the shelf life of 5ml bacteriostatic water after initial puncture?
Once the rubber stopper of a 5ml bacteriostatic water vial is punctured, standard laboratory guidelines recommend using or discarding the remaining liquid within 28 days when stored at controlled room temperature or refrigerated (2°C to 8°C).
What are the endotoxin limits for PX1 Research 5ml bacteriostatic water?
PX1 Research 5ml bacteriostatic water undergoes USP <85> endotoxin testing and is certified to contain less than 0.25 EU/mL, ensuring compatibility with sensitive in vitro and preclinical research applications.
Can 5ml bacteriostatic water be frozen?
Freezing bacteriostatic water is not recommended. Freezing can cause benzyl alcohol phase separation, compromise container closure integrity, or cause the glass vial to crack due to expansion.
Does benzyl alcohol interfere with cell culture assays?
At high concentrations, benzyl alcohol can exhibit cytotoxic effects in certain primary cell lines. For sensitive cell culture assays, researchers should calculate final diluted bench concentrations or utilize unpreserved sterile single-use water if preservatives impact the targeted assay endpoint.
How should unopened 5ml bacteriostatic water be stored?
Unopened vials should be stored at controlled laboratory room temperature (20°C to 25°C / 68°F to 77°F) protected from direct sunlight and extreme thermal fluctuations.
Is PX1 Research 5ml bacteriostatic water manufactured in the USA?
Yes. All PX1 Research diluents and laboratory reagents are manufactured in USA-based, GMP-compliant facilities and tested by independent ISO 17025 accredited laboratories.
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.