Bacteriostatic Water

About Bacteriostatic Water

Bacteriostatic water for injection (BWFI) is sterile, non-pyrogenic water containing 0.9% (w/v) benzyl alcohol as a bacteriostatic preservative. It is supplied in a sealed multi-dose vial designed to be punctured multiple times for sequential withdrawal of small volumes without compromising sterility of the bulk solution. The benzyl alcohol preservative inhibits the growth of common contaminating organisms, supporting multi-day use of the same vial under standard laboratory cold-chain conditions.

Why it matters for peptide research

Bacteriostatic water is the conventional solvent for reconstituting lyophilised research peptides in vitro. The 0.9% benzyl alcohol concentration is low enough to be compatible with most peptide structures while providing meaningful resistance to microbial growth in reconstituted stocks. Plain sterile water (without preservative) is acceptable for single-use immediate-prep workflows; bacteriostatic water is preferred when the reconstituted solution will be drawn from over multiple working sessions.

Storage

Store unopened vial at room temperature, protected from light. Once punctured, refrigerated storage at 2 to 8°C extends working life of the multi-dose vial. Discard if visible cloudiness, particulate matter, or discolouration develops.

Format

• Composition: sterile water for injection (USP grade) with 0.9% (w/v) benzyl alcohol preservative
• Vial sizes: 3 mL and 10 mL multi-dose
• Container: sealed glass vial with rubber septum suitable for repeated needle puncture
• Sterility: manufactured under sterile fill conditions; supplied non-pyrogenic