Navigating biochemical terminology requires precise understanding of chemical names, pharmacopeial standards, and functional classifications. This technical guide outlines the official bac water name, its exact chemical composition, regulatory designations, and handling protocols for laboratory peptide reconstitution.
Navigating biochemical terminology requires precise understanding of chemical names, pharmacopeial standards, and functional classifications. This technical guide outlines the official bac water name, its exact chemical composition, regulatory designations, and handling protocols for laboratory peptide reconstitution.
The official scientific bac water name is Bacteriostatic Water for Injection (BWFI), chemically defined as sterile, non-pyrogenic water containing 0.9% (9 mg/mL) benzyl alcohol added as an antimicrobial preservative. Laboratory literature also classifies it under technical synonyms including benzyl alcohol-preserved water, sterile bacteriostatic diluent, and preserved reconstitution medium.
While colloquially abbreviated as 'bac water' in experimental laboratories, formal procurement and laboratory inventories require referencing the compound by its exact USP (United States Pharmacopeia) title or chemical specification to distinguish it from unpreserved sterile water or bacteriostatic sodium chloride solutions.
To properly categorize the compound in laboratory management systems, researchers must understand its multi-component chemical formulation. The primary solvent component is highly purified, deionized water ($H_2O$, CAS Registry Number 7732-18-5). The bacteriostatic agent present at a concentrated 0.9% weight-by-volume ($w/v$) ratio is benzyl alcohol ($C_7H_8O$, IUPAC name: phenylmethanol, CAS Registry Number 100-51-6).
The presence of phenylmethanol alters the physical properties of the aqueous matrix slightly, lowering surface tension and establishing an environment that inhibits bacterial replication through cell membrane disruption. When logging reagents for analytical assays or reconstitution protocols, specifying '0.9% Benzyl Alcohol Aqueous Solution (Sterile)' ensures precise lot tracking and regulatory compliance.
In scientific literature and chemical catalogs, multiple terms are used interchangeably to describe bacteriostatic water. However, subtle differences in terminology denote specific grades, additions, or regulatory standardizations.
Standard industry terms include: 'Bacteriostatic Water for Injection' (the USP monograph title), 'Preserved Sterile Water for Reconstitution' (common in preclinical trial documentation), '0.9% Benzyl Alcohol Water' (chemical identifier), and 'BAC Water' (standard laboratory shorthand). It is essential to differentiate preserved water from isotonic bacteriostatic saline (0.9% NaCl with benzyl alcohol), as sodium chloride ions can alter the solubility profiles of specific hydrophobic peptides or induce precipitation in sensitive protein structures.
Unpreserved sterile water (Sterile Water for Injection) is susceptible to rapid microbial contamination once an vial septum is pierced. Microscopic introduction of airborne bacteria, fungi, or environmental pathogens can lead to exponential microbial growth in multi-dose lab containers.
The inclusion of 0.9% benzyl alcohol serves as a bacteriostatic agent. Rather than functioning primarily as an immediate bactericidal agent that rapidly denatures all biochemical structures, benzyl alcohol functions bacteriostatically by inserting its lipophilic phenyl ring into bacterial cell membranes. This increases membrane fluidity, disrupts membrane-bound transport proteins, and halts bacterial cellular division. In vitro studies confirm that this concentration effectively prevents microbial proliferation over extended multi-puncture sampling periods without altering the structural integrity of reconstituted research molecules.
Selecting the appropriate solvent matrix is a critical variable in preclinical research. Different lyophilized peptides require specific pH, ionic strength, and preservation parameters to maintain secondary and tertiary molecular conformation over multi-week research schedules.
In comparative preclinical assays, researchers evaluate three primary reconstitution fluids: bacteriostatic water, unpreserved sterile water, and bacteriostatic normal saline. For long-term multi-dose assays involving lyophilized compounds such as BPC-157, TB-500, and CJC-1295 DAC, preserved bacteriostatic water is standard because it prevents microbial growth after repeated vial entry. Unpreserved sterile water is restricted to single-use analytical procedures where organic preservatives like benzyl alcohol might interfere with mass spectrometry signals or UV absorbance assays.
Lyophilized research peptides are synthesized and purified via Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) before being freeze-dried into stable cakes. To prepare these compounds for in vitro testing or animal model assays, they must be reconstituted into stable liquid solutions.
When executing protocols detailed in our peptide reconstitution guide, introducing quality-verified bacteriostatic water ensures that the peptide remains solubilized and protected from bacterial degradation. The 0.9% benzyl alcohol concentration maintains sterility in the solution, allowing researchers to draw multiple aliquot samples over a 28-day experimental window when stored at recommended refrigeration temperatures ($2^\circ\text{C}$ to $8^\circ\text{C}$).
Not all commercially available solvents meet the strict requirements of cell culture or preclinical animal research. Low-grade diluent media can introduce heavy metals, organic impurities, or bacterial endotoxins (lipopolysaccharides) that cause inflammatory responses in animal models or distort in vitro cellular signaling assays.
At PX1 Research, every lot of bacteriostatic water and associated research diluents undergoes stringent quality control testing at ISO 17025 accredited analytical laboratories. Verification includes chromogenic Limulus Amebocyte Lysate (LAL) assays ensuring endotoxin levels remain strictly under $<0.25\text{ EU/mL}$, alongside High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS) to confirm the exact 0.9% benzyl alcohol assay and freedom from volatile organic impurities.
Maintaining the integrity of bacteriostatic water requires adhering to aseptic laboratory techniques. When accessing vials for peptide reconstitution, the rubber septum must be sanitized using a 70% isopropyl alcohol swab and allowed to air-dry completely prior to needle insertion.
Unopened vials of research-grade bacteriostatic water should be stored at controlled room temperature ($20^\circ\text{C}$ to $25^\circ\text{C}$) away from direct light. Once pierced, the vial should be maintained under refrigerated conditions ($2^\circ\text{C}$ to $8^\circ\text{C}$) and used within 28 days. After 28 days, the bacteriostatic efficacy of the benzyl alcohol may decline, increasing the risk of subtle microbial contamination in stored peptide solutions. Detailed analytical data and storage parameters are indexed in the PX1 research library.
Achieving reproducible, publication-quality experimental results requires absolute consistency across all reagents, from primary research peptides to reconstitution diluents. PX1 Research is dedicated to providing USA-manufactured compounds produced in state-of-the-art, GMP-compliant facilities.
Principal investigators and laboratory managers can review verified lot-specific Certificates of Analysis (COAs) for our full catalog of research peptides and reconstitution supplies. We offer fast logistics—including same-day dispatch for orders placed Monday through Friday before cut-off times from our dual distribution centers in California and Arizona—as well as dedicated bulk lab account options for high-throughput research institutions.
What is the official scientific name for bac water?
The official scientific name for bac water is Bacteriostatic Water for Injection (BWFI). Its chemical definition is sterile, non-pyrogenic water containing 0.9% (9 mg/mL) benzyl alcohol as an antimicrobial preservative.
Is bac water the same as sterile water?
No. Sterile water contains no preservatives and is designed for single-use applications. Bac water contains 0.9% benzyl alcohol, which inhibits bacterial growth and allows the vial to be accessed multiple times over a 28-day period in laboratory settings.
What is the CAS number for bacteriostatic water?
Bacteriostatic water is a two-component mixture: purified water (CAS 7732-18-5) and benzyl alcohol (CAS 100-51-6) present at a 0.9% concentration.
Why is 0.9% benzyl alcohol added to research-grade water?
Benzyl alcohol at 0.9% acts as a bacteriostatic preservative by disrupting bacterial cell membranes, preventing bacterial multiplication without altering the stability of reconstituted peptides or proteins.
How long does bacteriostatic water remain stable after opening?
Once the vial septum has been pierced, bacteriostatic water is rated for multi-dose laboratory use for up to 28 days when stored under refrigerated conditions (2°C to 8°C).
What endotoxin levels are acceptable for laboratory reconstitution water?
Research-grade bacteriostatic water must maintain endotoxin levels below 0.25 EU/mL, verified via chromogenic LAL testing, to prevent immune activation or cellular toxicity in preclinical models.
Can bacteriostatic normal saline be used instead of bac water?
Bacteriostatic saline contains 0.9% sodium chloride in addition to benzyl alcohol. While suitable for some applications, the high ionic strength of saline can cause hydrophobic peptides to precipitate out of solution, making standard bacteriostatic water the preferred universal diluent.
Where does PX1 Research manufacture and ship its reconstitution diluents?
All PX1 Research products are USA-manufactured in GMP-compliant facilities and undergo ISO 17025 third-party verification. Orders ship same-day M–F from our primary distribution hubs in California and Arizona.
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.