Both are used to reconstitute lyophilized peptides, but they are not interchangeable in every protocol.
Sterile water
Sterile water contains no additives. It suits single-use preparations, where the entire vial is used at once.
Bacteriostatic water
Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits bacterial growth. That makes it the usual choice when a vial will be accessed several times over a period of days.
| Sterile water | Bacteriostatic water | |
|---|---|---|
| Preservative | None | 0.9% benzyl alcohol |
| Typical use | Single use | Multiple draws |
| After opening | Use immediately | Refrigerate, use within protocol limits |
Compatibility
A small number of compounds are sensitive to benzyl alcohol or need acidic or buffered diluents. Always check the solubility information for the compound you are working with.
