Bacteriostatic Water vs Sterile Water: What's the Difference?
Bacteriostatic water vs sterile water for the lab: the 0.9% benzyl alcohol preservative, single-use vs multi-draw vials, and storage after opening.
The short answer
Both are purified, sterile water. Bacteriostatic water has 0.9% benzyl alcohol added as a preservative, which holds back bacterial growth so a vial can be drawn from more than once. Sterile water has nothing added and is meant to be used once.
Why the preservative matters
Every time a stopper is punctured there is a chance of introducing bacteria. In a vial with no preservative, anything introduced can grow. Benzyl alcohol keeps that growth in check, which is what makes a multi-draw vial practical in the lab.
Storage
Keep vials at controlled room temperature and away from light until opened. Once opened, date the vial. A common lab practice for multi-draw vials is to discard them 28 days after first opening.
What we stock
We carry 30 mL bacteriostatic water vials preserved with 0.9% benzyl alcohol, listed under Supplies.
Everything sold on this site is for in vitro research and laboratory use only.