BAC Water

Bacteriostatic Water (USP, BWFI) is a sterile, multi-dose laboratory reconstitution solvent — USP-grade sterile water preserved with 0.9% benzyl alcohol as a bacteriostatic agent. The peer-reviewed literature catalogs bacteriostatic water as the standard solvent for reconstituting lyophilized peptide reference standards in research workflows where multiple withdrawals from a single vial are anticipated. The benzyl alcohol preservative inhibits microbial growth between withdrawals, distinguishing BWFI from non-preserved Sterile Water (USP, SWFI), which is single-use only. Composition is fixed by USP monograph specification: USP-grade sterile water and benzyl alcohol 0.9% w/v. The product supplied here is intended for laboratory reconstitution work only. For research use only; not for human consumption, medical use, or veterinary application. Researchers should reference USP monograph and supplier specifications for context-specific compatibility.

Experimental contexts documented in laboratory practice include reconstitution of lyophilized peptide reference standards for in-vitro and animal-model research, preparation of working stocks for HPLC and mass spectrometry analytical-method development, and as the standard solvent for assay-buffer dilution series where a sterile, bacteriostatic preservative is appropriate. Researchers select between BWFI and non-preserved SWFI based on the downstream assay's sensitivity to benzyl alcohol — most peptide-research workflows tolerate benzyl alcohol at 0.9%, but some cell-culture systems and certain peptide stability assays prefer SWFI. The product is supplied for these and equivalent in-vitro and analytical experimental contexts only, with no associated guidance for human, clinical, or veterinary application. Researchers should consult supplier specifications and assay-specific compatibility documentation when designing context-specific protocols.