Bacteriostatic Water 3ml

Bacteriostatic water is sterile water to which 0.9% benzyl alcohol (9 mg per mL) has been added. The benzyl alcohol acts as a preservative. It holds back the multiplication of bacteria that might enter once the stopper has been pierced, but it does not kill microbes already present, which is why the water must be sterile from the start.

That preservative is the one feature separating it from plain sterile water. In laboratory handling, its practical effect is that a single vial can be accessed more than once over a defined period, provided aseptic technique is kept up throughout.

Made to a pharmacopoeial standard

The USP monograph for bacteriostatic water sets the benzyl alcohol level, sterility and endotoxin limits, and a pH range of 4.5 to 7.0. Our bacteriostatic water guide explains these properties in more depth.

Where it fits on the bench

Remy Research lists this ProPeptide vial as a preserved laboratory diluent to keep beside lyophilised research vials. The 3mL fill suits a bench that only ever needs a modest volume at one time.

A small fill means less waste

A compact vial leaves less unused liquid behind when its in-use window ends. Labs handling many vials may prefer the larger ZPHC fills in 11mL or 40mL.

Date the label on first opening

Remy's guide applies a common 28-day rule: write the date of first puncture on the vial and discard it after 28 days unless the manufacturer states a different period, even if liquid remains.

When preservative-free water is the better fit

Benzyl alcohol is not compatible with everything. Our comparison of bacteriostatic and sterile water notes it can interfere with some assays, cell systems and proteins. The guide also names oxytocin, vasopressin and hCG as peptides that call for preservative-free sterile water instead.