What Is Bacteriostatic Water?
Bacteriostatic water for injection (BAC Water) is sterile water for injection containing 0.9% benzyl alcohol as a bacteriostatic preservative. The benzyl alcohol inhibits microbial growth for up to 28 days after the vial is first punctured, making BAC Water the standard choice for reconstituting lyophilised research peptides that will be used across multiple research sessions.
Why BAC Water vs Sterile Water?
| Property | BAC Water | Sterile Water | |---|---|---| | Benzyl alcohol | 0.9% (bacteriostatic) | None | | Multi-use after opening | Up to 28 days | Single use only | | Microbial growth inhibition | Yes | No | | Peptide stability | Excellent | Good (use immediately) |
For any peptide vial that will be used more than once, BAC Water is the appropriate choice. Sterile water should only be used when the entire reconstituted volume will be used in a single experiment.
Reconstitution Protocol
- Calculate volume: Determine the concentration needed (e.g., 2 mg peptide + 2 mL BAC Water = 1 mg/mL)
- Swab both rubber stoppers with an alcohol wipe and allow to dry
- Draw BAC Water into a sterile syringe
- Inject slowly down the side of the peptide vial — never inject directly onto the lyophilised cake, as high-pressure injection can denature the peptide
- Gently swirl the vial (do not shake) until fully dissolved
- Label the vial with reconstitution date and concentration
- Store at 2–8°C (refrigerator) and use within 28 days
Storage After Reconstitution
- Reconstituted peptides should be stored at 2–8°C, not frozen
- Keep away from light and heat
- Discard if cloudiness or particulates appear
- Lyophilised (unreconstituted) peptide should be stored at −20°C
Research Notes
BAC Water is a consumable supply, not a research compound. Each Peptyde Co. BAC Water vial is pharmaceutical grade, sterile, and pyrogen-tested.
Used with: All lyophilised peptides — BPC-157, TB-500, Ipamorelin, CJC-1295, and all others in our catalogue.