Bacteriostatic water for peptides (10 mL and 30 mL)

What is bacteriostatic water?

Sterile, non-pyrogenic water containing 0.9% benzyl alcohol as a bacteriostatic preservative, supplied in a sealed multi-dose vial. The preservative inhibits bacterial growth in the vial after the stopper has been punctured, which is what makes it the standard diluent for reconstituting lyophilised peptides that will be drawn from more than once. Plain sterile water (no preservative) is for single-use reconstitution only.

Which size?

The 10 mL vial reconstitutes several peptide vials at typical volumes of 1 to 3 mL each. The 30 mL vial suits laboratories running many reconstitutions or larger diluent volumes. Both are sealed, USP-grade, and should be discarded 28 days after the first puncture regardless of how much remains.

Bacteriostatic water 10ml suits most researchers; bacteriostatic water 30ml suits higher throughput. Both are in UK stock.

Using it with our peptides

Swab both stoppers, draw the required volume, and add it slowly down the inside wall of the peptide vial rather than onto the powder; swirl, do not shake. The calculator converts vial amount and diluent volume into concentration and syringe units. Storage of reconstituted peptides is given on each product page.

Bacteriostatic vs sterile water

Bacteriostatic water: preserved, multi-dose, 28-day in-use life. Sterile water for injection: unpreserved, single use, discard the remainder. Never use tap, bottled or boiled water: not sterile, wrong pH, and it will degrade the peptide.

Bac water: the same thing

Bac water, BAC water and bacteriostatic water are one product: sterile water with 0.9% benzyl alcohol. Searches for bac water UK usually want exactly this, a multi-dose vial that can be drawn from repeatedly for reconstituting research peptides. Our bacteriostatic water guide covers how it differs from plain sterile water.

Sizes and pricing

• Bacteriostatic Water 10mL: £5.99. SKU BAC-10.
• Bacteriostatic Water 30mL: £10.99. SKU BAC-30.

Prices include VAT. Shipping is £4.95 by Royal Mail Tracked 24, free on orders over £100. Ships from UK stock with the lot certificate for the vial you receive.

Quality and testing

Each lot of Bacteriostatic Water is sent to an independent UK laboratory before release for identity by mass spectrometry, purity by HPLC, residual solvents and bacterial endotoxin. The lot number on the vial label matches the certificate on our certificates page, and no lot is released for sale until the certificate is in hand. Specification: Sterile, USP grade, supplied as sealed multi-dose vial.

Lot traceability

Every Bacteriostatic Water vial carries a printed lot number and expiry. The same lot number appears on the certificate of analysis for that batch, which names the testing laboratory and the report number so it can be verified directly. If the number on your vial does not match a certificate on our site, contact support before using it. Certificates are kept online for the life of the product plus two years.

Related products

Insulin Syringes 1 mL, Alcohol Prep Swabs, BPC-157, and everything else in Water & Accessories or the full range. Reconstitution supplies: bacteriostatic water, insulin syringes and alcohol swabs.

Handling and storage

Room temperature, discard 28 days after first puncture. Keep sealed until use. Allow the vial to reach room temperature before opening to avoid condensation on the powder. Reconstitute with bacteriostatic water added slowly down the wall of the vial; do not shake. Our calculator covers the arithmetic.