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0.9% benzyl-alcohol bacteriostatic reconstitution diluent (multi-use)
Overview
Bacteriostatic Water for Injection (BAC Water) is sterile water containing 0.9% benzyl alcohol as a preservative, used as a multi-use reconstitution diluent. The benzyl-alcohol preservative inhibits microbial growth in a vial whose septum has been pierced repeatedly, supporting multi-dose use over the conventional ~28-day window after first puncture (the USP-compendial expectation for preserved injectable solutions). For preservative-compatible peptides it is the workhorse diluent in workflows where a single vial supports many small aliquots over a multi-week period. It is supplied as a characterized ancillary diluent rather than a research-target molecule. Lyochem supplies BAC Water in sterile vial formats prepared from pharmaceutical-grade benzyl alcohol and Water for Injection, with the benzyl-alcohol content documented explicitly on the label and release packet alongside sterility and endotoxin data. BAC Water is not universally compatible: some short peptides interact with benzyl alcohol, and for those preservative-free Sterile Water for Injection in single-use aliquots is the recommended alternative. Confirm the recommended diluent for the specific peptide on its COA before defaulting to BAC Water.
Applications & buyer fit
Solvents and ancillaries are the bench-support consumables a lab pairs with a reference standard once it leaves the freezer — bacteriostatic and sterile water, isotonic saline, 0.6% acetic-acid water, and glacial acetic acid for in-house diluent prep. These are diluents and process auxiliaries rather than research targets, so the documentation is diluent / solvent-grade (component identity, sterility, endotoxin, pH / osmolality, pharmacopeia monograph) rather than the peptide HPLC + MS + sequence packet. Diluent selection follows the peptide's stability profile: acidic-pH-requiring proteins use the acetic-acid water; preservative-incompatible peptides use sterile water; preservative-compatible peptides for multi-use vials use BAC water.
Academic Laboratories
Universities, medical schools, and government research institutes qualifying a reference standard for a method-development or in vivo workflow.
Core Facilities & Instrumentation Cores
Shared instrumentation cores, mass-spec facilities, and departmental analytical labs holding reference standards for cross-PI method validation and reagent qualification.
Contract Research Organisations (CROs)
CROs running preclinical and translational studies on behalf of academic, biotech, or pharma sponsors who need traceable reference material across multi-site campaigns.
Every release ships with its own batch-specific CoA — identity, purity, and the analytical scope agreed at quote stage, tied to the exact lot you receive.
Review a representative batch CoA before you order, so you can confirm the packet matches what your method or sponsor audit needs.
Supplied strictly as a research reagent to research institutions — not a finished dosage form and not for human administration. Buyer qualification runs at the inquiry stage.
Specifications
Documentation available on request
Regulatory note
Reconstitution diluent containing benzyl-alcohol preservative; supplied for Research Use Only. Not universally compatible with all peptides — some require preservative-free SWFI. Verify sterility, endotoxin, and injectable-grade compliance with the destination market's requirements before use.
Frequently asked questions
Use BAC Water when the peptide is preservative-compatible and the workflow benefits from a multi-use vial — the 0.9% benzyl alcohol prevents microbial growth after multiple septum punctures, supporting many small aliquots over weeks. Use Sterile Water for Injection when the peptide is preservative-incompatible (some short peptides interact with benzyl alcohol), when the preparation is single-use within hours, or when the downstream work requires preservative-free chemistry. The recommended diluent per standard is noted on its COA.
It is the USP-compendial expectation for preserved injectable solutions and the conservative operational default, but actual stability depends on the specific peptide and storage conditions — some peptides warrant a shorter window, others tolerate longer. The 28-day default suits most reference-standard reconstitutions held refrigerated; stability for a specific peptide-in-diluent combination is an empirical question for the lab's own protocol.
The benzyl-alcohol content is stated explicitly on the product label and the release packet, alongside sterility and endotoxin data, so a lab can confirm preservative compatibility for its peptide before use. Where a peptide is benzyl-alcohol-incompatible, the preservative-free SWFI diluent is the documented alternative.
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