Bacteriostatic Water

Overview

Bacteriostatic water is sterile, purified water to which 0.9% (v/v) benzyl alcohol has been added. The benzyl alcohol inhibits the growth of most bacteria that might be introduced when a multi-use vial is punctured repeatedly, which is why laboratories prefer it over plain sterile water for preparing peptide solutions that will be drawn from more than once.

Acu Aminos supplies bacteriostatic water in sealed 3 mL and 10 mL vials; choose the size above. The 10 mL size suits laboratories preparing several peptide stocks from one vial.

Chemistry & specifications

Benzyl alcohol (C₇H₈O) is an aromatic alcohol with broad bacteriostatic activity at 0.9% concentration. It does not sterilize; it slows microbial growth after the seal is broken. The water is USP-grade purified water, sterile-filtered and filled under aseptic conditions. Because benzyl alcohol can precipitate some proteins at high concentration, and is unsuitable for certain sensitive cell-culture applications, researchers should confirm compatibility with their assay.

Cellular structure & mechanism of action

Benzyl alcohol acts by disrupting bacterial cell membranes and inhibiting enzyme activity, slowing the replication of most common contaminants for the labeled in-use period (typically 28 days after first puncture). It has no effect on the peptide itself and does not alter the chemistry of a lyophilized compound once dissolved. It is not suitable as a diluent for every application; some cell-culture protocols require preservative-free sterile water or buffered saline instead.

Research applications

• Preparation of research-peptide stock solutions from lyophilized powder
• Multi-draw laboratory diluent where a preservative is required
• Analytical sample preparation for HPLC and LC-MS

Selected references

1. United States Pharmacopeia. Bacteriostatic Water for Injection monograph; General Chapter <51> Antimicrobial Effectiveness Testing.
2. Meyer BK, Ni A, Hu B, Shi L. Antimicrobial preservative use in parenteral products: past and present. J Pharm Sci. 2007;96(12):3155–3167.

References are provided to help researchers locate primary literature. Acu Aminos makes no claims about the safety or efficacy of any compound in humans or animals.