The diluent, properly specified
Sterile water preserved with 0.9% benzyl alcohol, so a vial can be entered more than once. Three formats. Australian stock, dispatched daily.

One reconstitution, zero waste. Break, draw, done.

The workhorse. Multi-dose, refrigerate, withdraw for weeks.

Five sealed ampoules, $5 saved. The bench supply.
| Format | Volume | Price | Cost per mL | Best for |
|---|---|---|---|---|
| 10mL ampoule | 10mL | $4 | 40c | Single use: one reconstitution, no storage |
| 30mL vial | 30mL | $25 | 83c | Multi-dose work: repeated entry over weeks, refrigerated |
| 5 x 10mL pack | 50mL | $15 | 30c | Bench supply: single-use format, lowest cost per mL, no refrigeration |
Buy three of one size and the fourth ships free. $15 flat shipping Australia wide, free over $200.
Bacteriostatic water is sterile water preserved with 0.9% benzyl alcohol. The preservative inhibits bacterial growth inside the vial between entries, and that single property is what makes multi-dose use possible. Without it, an opened vial is single use by design.
BuyBac supplies lab grade bacteriostatic water in three formats, held in stock in Perth and dispatched daily Australia wide. Every order ships in plain packaging with research consumable labelling.
| Property | Specification |
|---|---|
| Base | Sterile water, laboratory grade |
| Preservative | Benzyl alcohol 0.9% v/v |
| pH range | 4.5 to 7.0 |
| Formats | 10mL ampoule, 30mL multi-dose vial, 5 x 10mL pack |
| Labelling | Research consumables, plain and discreet |
| Dispatch | Daily from Perth, Western Australia |
| Shipping | $15 flat Australia wide, free over $200 |
The benzyl alcohol in bacteriostatic water exists for one purpose: to keep a punctured vial usable. A 0.9% concentration is bacteriostatic rather than sterilising. It inhibits bacterial growth between entries; it does not sterilise a dirty entry and it does not replace technique.
That is why the discipline around the vial stays the same regardless of brand. Wipe the septum with a fresh sterile pad and let it dry before piercing. Use a fresh sterile entry consumable for every draw. Refrigerate the vial between sessions and date it on first entry. Discard immediately on cloudiness, particulates or any colour change, regardless of the calendar.
Handled this way, a 30mL multi-dose vial serves a protocol across weeks, which is exactly the job it was designed for. The preservative is the safety net that makes repeated entry viable; aseptic technique does the rest.
Sterile water contains no preservative. The moment the stopper is pierced, the contents are no longer protected, which is why sterile water is labelled single use by design. Bacteriostatic water is sterile water with the 0.9% benzyl alcohol preservative added, and that difference is what permits repeated aseptic entry over weeks.
The practical version: one entry and done, the 10mL ampoule covers it either way. Multi-entry work needs bacteriostatic water. The full comparison, including where each product belongs and why the packaging looks the same but behaves differently, is in the sterile versus bacteriostatic comparison. And if you arrived here asking whether major retail chains stock it, the short answer is no: the pharmacy question, answered explains what pharmacy shelves actually hold.
Sealed ampoules and vials store at room temperature, away from direct light, until opened. Once a multi-dose vial is entered, refrigerate it and treat the clock as running: weeks of usability, not months, and discard on any sign of change rather than on a date alone.
Ampoules behave differently. Each 10mL ampoule stays sterile until broken and is single use by design, so there is no storage decision to make. Break, draw, use, discard the remainder. For bench supply across multiple reconstitutions, the 5 x 10mL pack keeps every entry sealed until the moment it is used.
BuyBac holds stock in Perth and dispatches every business day. Orders ship Australia wide at $15 flat, free once an order passes $200, in plain packaging with nothing on the label but a research consumable description. No account is needed and there is no minimum order. If you are weighing up suppliers, the guide to where to buy bacteriostatic water in Australia covers what to check before you order anywhere.
Metro capitals typically receive orders within two working days. Perth customers have the fastest turnaround in the country: same day pickup most days, or metro delivery within a day or two. City specific details, delivery windows and pickup notes live on the Perth, Sydney, Melbourne and Brisbane pages.
For bulk or recurring bench supply, or a question this page does not answer, the contact desk answers the same business day.