If a supplied lot fails agreed specifications, we’ll replace it at no cost or refund its purchase price in full.
Quality test failed? Free replacement or full refund.
Off-spec? Free replacement or full refund.
Reading a Peptide HPLC Trace — A 5-Minute Field Guide for Bench Scientists. Read our briefing →
Reading a peptide HPLC trace — a field guide. Read →
On reading HPLC traces. Read →
Research reagent · Research use only
0.9% benzyl-alcohol bacteriostatic reconstitution diluent (multi-use)
Price, MOQ and lead time come in your written quote — usually within 24 hours. No account needed.
Compound facts
| Name | BAC Water |
|---|---|
| CAS number | (blend, components: benzyl alcohol 100-51-6, water 7732-18-5) |
| Appearance | Clear, colorless liquid |
| Purity specification | ≥ 99.0% (component-wise for blends) |
| Batch COA | Every lot has its own batch COA; the tests are listed on it. |
| Storage | Room temperature, protect from light |
| Fill sizes | 3 ml · 5 ml · 10 ml · 30 ml |
| Pack | 10 vials per kit |
| MOQ | On request |
| Lead time | 7–14 days |
| Use | Research use only — not for human or veterinary use |
Identity data from the Lyochem product catalogue. The batch COA of your lot is the record for that lot's results. How to verify a COA
Lot documentation
Every lot has its own batch COA; the tests performed are listed on it.
Values belong to the lot. Ask for the COA of the offered lot before you order.
Independent test fails? Full refund. How it works
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 3 ml, 10 ml, and 30 ml sterile vial formats prepared from pharmaceutical-grade benzyl alcohol and Water for Injection, with the benzyl-alcohol content stated explicitly on the label and the batch COA; sterility and endotoxin data are available on request and listed on the COA when tested. 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, 0.6% acetic-acid water, and the benzyl-alcohol preservative used in multi-use diluent prep. These are diluents and process auxiliaries rather than research targets, so the documentation is diluent / solvent-grade (component identity, sterility, endotoxin, osmolality where applicable, 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 lot has its own batch-specific CoA — RP-HPLC purity, ESI-MS identity, bacterial endotoxin and fill amount, plus any 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.
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
The benzyl-alcohol concentration is stated explicitly on the product label and the batch COA, so a lab can check preservative compatibility against its specific peptide before the vial is opened; sterility and endotoxin data are available on request and listed on the COA when tested. This matters because some short peptides interact with benzyl alcohol, and for those the documented preservative-free Sterile Water for Injection is the alternative diluent. The recommended diluent for a given reference standard is noted on that standard's own COA, so the pairing is traceable rather than assumed.
Per USP convention it is the expected window for preserved injectable solutions and a conservative operational default, not a hard per-peptide limit. The 0.9% benzyl alcohol suppresses microbial growth after repeated septum punctures, which supports the multi-use window, but the actual in-solution stability of a specific peptide-in-diluent combination is an empirical question for the lab's own protocol: some warrant a shorter window, others tolerate longer. The 28-day default suits most reference-standard reconstitutions held refrigerated, with peptide-specific stability confirmed against the intended assay.
Send any vial from your order to an independent laboratory of your choice. If the report shows the product does not meet the specification on its COA — purity below the stated minimum, or an identity that does not match — share the report with our sales team and we refund that product in full.
Related peptides