Bacteriostatic Water
0.9% benzyl alcohol water · Bacteriostatic diluent
Sterile water with 0.9% benzyl alcohol, for reconstitution where a solution is held for several weeks.
Total, ex VAT
£7.50
- Released at Sterile, 0.9% w/v benzyl alcohol
- Identity confirmed by ESI-MS against theoretical mass
- Batch certificate matched to the vial, verifiable online
- Same working day dispatch before 14:00, tracked
For laboratory research use only. Not for human or veterinary use, and not a medicine, food or cosmetic. Sold to qualified researchers and institutions who accept responsibility for safe handling and lawful use.
Compound data
What is in the vial
Indicative values for this line. The certificate issued with your batch is the authoritative record and reports the measured figures for the material you receive.
- CAS number
- Stated on certificate
- Molecular formula
- H2O + 0.9% w/v benzyl alcohol
- Average mass
- n/a
- Class
- Preserved aqueous diluent
- Form as supplied
- Lyophilised powder
- Appearance
- White to off-white lyophilised powder
- Purity specification
- Sterile, 0.9% w/v benzyl alcohol
- Solubility
- n/a
- Storage
- Room temperature, 15–25 °C. Do not freeze.
Overview
About Bacteriostatic Water
Bacteriostatic water is sterile water containing 0.9% benzyl alcohol as a preservative. The preservative is what allows a multi-withdrawal vial to be used over weeks rather than being discarded after a session, and it is the standard diluent where a reconstituted peptide solution will be held at 2–8 °C for an extended period.
It is not always the right choice. Benzyl alcohol absorbs in the UV region used by many detection methods and can interfere with downstream analysis; it is also incompatible with a small number of compounds. Where a solution will be used promptly or must not carry a preservative, sterile water is the correct diluent instead.
In short
- Sterile water with 0.9% w/v benzyl alcohol preservative
- Suitable for multi-withdrawal use over weeks at 2–8 °C
- Benzyl alcohol absorbs in the UV — check compatibility with your detection method
- Store at room temperature; do not freeze
Where it is used
Research applications
Extended solution storage
The preservative allows a working vial to be drawn from repeatedly over several weeks without microbial growth.
Reconstitution of lyophilised material
The standard diluent for lyophilised peptides across the catalogue, subject to compound compatibility.
Method compatibility
Where UV detection is used, the benzyl alcohol absorbance needs accounting for — sterile water avoids this entirely.
Handling
Reconstitution and stability
Reconstitution
Reconstitute with sterile or bacteriostatic water added slowly against the inner wall of the vial. Allow the cake to dissolve without agitation, swirling gently if required. Do not vortex or shake.
Stability
Lyophilised at −20 °C, desiccated and protected from light, stable for at least 24 months. Reconstituted and held at 2–8 °C, use within 28 days. Avoid repeated freeze-thaw.
Notes
- Bring the vial to room temperature before opening so atmospheric moisture does not condense onto cold powder.
- Record the reconstitution date on the vial; concentration drift between runs is usually evaporation, not synthesis variance.
- Aliquot at first reconstitution where the working programme needs more than a few withdrawals.
Laboratory reference
Reconstitution calculator
Enter the fill weight on the vial and the diluent volume you intend to add. The calculator returns the resulting solution concentration and the volume that contains a given mass.
- Concentration
- 5.000 mg/mL · 5000 µg/mL
- Volume containing target mass
- 50.0 µL · 0.0500 mL
Figures are mass-to-volume arithmetic for laboratory preparation of Bacteriostatic Water and take no account of net peptide content, which is stated on the batch certificate and should be applied to the fill weight before calculating. Nothing here constitutes dosing, administration or clinical guidance of any kind.
Published work
What the literature reports
Summaries of published findings, provided as research reference. These describe work done by others in preclinical and clinical settings; they are not claims about this material or outcomes for any reader.
Preservative efficacy
Benzyl alcohol at 0.9% is the long-established concentration for bacteriostatic aqueous diluents in laboratory and pharmaceutical use.
Pharmacopoeial monographs
Compatibility considerations
Preservative interference with UV detection and with specific compound classes is well documented in analytical method development literature.
Reviewed in analytical chemistry method guidance
Questions
Bacteriostatic Water — asked and answered
Something not covered here? Ask us directly — technical questions reach someone who runs the assays.
- When should I use sterile water instead?
- When the solution will be used promptly, when the preservative would interfere with your detection method, or when a specific compound is incompatible with benzyl alcohol. For long-held solutions, bacteriostatic is the better default.
- Does the preservative affect assay results?
- It can. Benzyl alcohol absorbs in the UV region used by many detectors. Run a diluent blank if you are quantifying by UV.
- How should it be stored?
- Room temperature, 15–25 °C. Do not freeze — freezing can compromise the container seal.
Important
Bacteriostatic Water is supplied strictly for laboratory research and analytical use. It is not a medicine, food, cosmetic or veterinary product; it is not for human or animal consumption; and it is not intended to diagnose, treat, cure or prevent any condition. It is not manufactured, tested or released to any standard that would support administration to humans or animals. Information on this page is compiled for research reference and is not medical advice. No dosing, administration or therapeutic guidance is given or implied. By ordering you confirm you are a qualified researcher or institution and accept responsibility for safe handling and lawful use.