Bacteriostatic Water

Bacteriostatic Water for Injection (BWFI) 10 mL is USP-grade sterile water preserved with 0.9% benzyl alcohol (w/v) as a bacteriostatic agent. It is the standard reconstitution medium for lyophilized peptides and research compounds in laboratory settings. The benzyl alcohol preservative inhibits microbial growth through disruption of bacterial cell membrane integrity, allowing safe multi-use access from a single vial over an extended period — typically up to 28 days after the first needle puncture when stored properly. When reconstituting lyophilized peptides, BWFI should be added slowly along the wall of the vial, allowing the cake to dissolve gradually without vigorous shaking, which could damage peptide tertiary structure. For most peptides, a concentration of 1-2 mg/mL provides optimal stability. Reconstituted solutions should be stored at 2-8°C (refrigerated) and protected from light. This 10 mL format provides a larger volume for laboratories with higher reconstitution needs, supporting multiple peptide vials at standard research concentrations while eliminating the need for single-use sterile water aliquots.