BAC Water 30mL Multi-Dose Vials

    Peptx stocks 30mL multi-dose bacteriostatic water vials, the format most laboratories prefer for reconstituting lyophilised research peptides. One 30mL vial typically supports 10 to 30 reconstitutions depending on dose protocol.

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    Sterile USP grade
    0.9% benzyl alcohol
    30mL multi-dose
    Tracked worldwide

    What bacteriostatic water actually is

    Bacteriostatic water for injection (BWFI) is sterile water that has been treated with 0.9% benzyl alcohol, a mild bacteriostatic preservative. The preservative does not actively kill bacteria, but it prevents microbial growth within the vial, allowing the same multi-dose vial to be safely punctured and used repeatedly for up to 28 days after first opening.

    In research-peptide work, lyophilised peptides arrive as a dry powder that must be reconstituted before use. Bacteriostatic water is the standard diluent for this because laboratory work often draws from a single reconstituted vial over multiple weeks, and the bacteriostatic preservative allows that workflow without microbial contamination risk. Plain sterile water for injection, by contrast, is single-use only and must be discarded after first puncture.

    The 30mL multi-dose format that Peptx supplies is the workhorse size used across virtually all published peptide research protocols. One 30mL vial typically supports 10 to 30 separate peptide vial dilutions depending on the concentration used.

    How to use bacteriostatic water for peptide reconstitution

    1. Calculate the volume

    Concentration is determined by the diluent volume added relative to the peptide mass stated on the vial label, expressed in mg per mL.

    2. Add the diluent slowly

    Add the calculated volume of bacteriostatic water slowly down the inner wall of the vial, never directly onto the lyophilised powder, which can denature delicate sequences.

    3. Swirl, do not shake

    Gently swirl the vial in a circular motion until the powder fully dissolves. Vigorous shaking can degrade peptide chains and introduce foaming. The solution should be visually clear when ready.

    4. Refrigerate and label

    Refrigerate the reconstituted vial at 2 to 8 Celsius. Label with the reconstitution date and the achieved concentration. Most reconstituted research peptides are stable refrigerated for 4 to 6 weeks.

    Storage and shelf life

    • Unopened vials: stable at room temperature, away from direct sunlight, for the full labelled shelf life.
    • After first puncture: store refrigerated at 2 to 8 Celsius. Discard any unused portion 28 days after first puncture, per standard USP multi-dose guidance.
    • Reconstituted peptide vials: store refrigerated at 2 to 8 Celsius, protected from light, and use within 4 to 6 weeks for most research peptides.
    • Visual checks: the solution should remain clear and colourless. Discard any vial showing cloudiness, particulate matter, or discolouration.

    Bacteriostatic water FAQ

    What is bacteriostatic water?▼
    Bacteriostatic water is sterile water for injection preserved with 0.9% benzyl alcohol, a mild bacteriostatic preservative that prevents microbial growth in multi-dose vials. It is the standard diluent used to reconstitute lyophilised research peptides because it allows the same vial to be used multiple times over a 28-day window without microbial contamination concerns.
    What is the difference between bacteriostatic water and sterile water for injection?▼
    Sterile water for injection contains no preservative and must be used as a single-dose product, with any remainder discarded immediately after first puncture. Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits bacterial growth and allows the vial to be reused for up to 28 days after first puncture. Multi-dose use makes bacteriostatic water the preferred diluent for research peptide reconstitution.
    How much bacteriostatic water is used per vial?▼
    It depends on the concentration required by the study design. The volume of diluent added divided into the peptide mass on the vial label gives the resulting concentration in mg per mL.
    How should bacteriostatic water be stored?▼
    Store unopened bacteriostatic water vials at room temperature, away from direct sunlight. After first puncture, store in a refrigerator at 2 to 8 Celsius and discard any unused portion 28 days after first puncture, in line with the standard USP guidance for multi-dose preserved injectables.
    Can I buy bacteriostatic water without a prescription?▼
    Bacteriostatic water is sold as a research-grade reagent rather than a prescription pharmaceutical product. Peptx supplies it to research laboratories and B2B research buyers, with no prescription required for the research-grade format. It is supplied for in-vitro laboratory use only.
    Why is BAC water often hard to find?▼
    Retail pharmacies in many countries do not stock the 30mL multi-dose format because it is mainly used for peptide reconstitution in research and compounding settings. Research suppliers like Peptx maintain stock specifically for the research-peptide market.
    Do you ship BAC water internationally?▼
    Yes, Peptx ships bacteriostatic water worldwide with full tracking. Standard transit is 3 to 5 working days within the UK and 5 to 10 working days to most international addresses. BAC water is not a controlled or restricted item in any major jurisdiction.

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