BAC water (bacteriostatic water) is sterile water containing 0.9% benzyl alcohol as a preservative. It’s the standard solvent for reconstituting lyophilized research peptides. The benzyl alcohol inhibits bacterial growth in the reconstituted solution, extending stability from hours (with plain sterile water) to 30–60 days under refrigeration.
Why It’s Used
Lyophilized peptides need a liquid solvent to become usable in research protocols. Plain sterile water provides only ~24 hours of post-reconstitution stability before bacterial growth becomes a concern. BAC water’s preservative extends that window dramatically without affecting the peptide chemistry for the vast majority of research compounds.
The Standard Reconstitution Ratio
The most common research-method ratio: 2 mL BAC water per 10 mg peptide, producing a 5 mg/mL solution. Other concentrations are valid — the choice is driven by your protocol and the syringe units you’ll be drawing.
Use the reconstitution calculator for any vial size and concentration.
Storage
- Unopened BAC water: room temp, stable 24+ months
- After first puncture: refrigerate optional; in-use stability typically 28 days per manufacturer label
- Reconstituted peptide solutions: refrigerated 36–46°F, 30–60 days stable
Matte stocks BAC water in 3 mL and 10 mL sizes.
Research use only. Not for human consumption. Statements not evaluated by the US FDA.