Search for “bacteriostatic water 10ml” and you will find a range of products, from single vials to multi-packs, sold as diluents for reconstituting lyophilised peptides. The 10ml size is one of the most common because it is convenient for a reasonable number of reconstitutions without being so large that the preservative degrades before the bottle is used.

This guide explains how many reconstitutions a 10ml vial of bacteriostatic water covers, how the volume per reconstitution is determined, and what to consider when choosing the size for a research protocol.

What bacteriostatic water 10ml is

Bacteriostatic water is sterile water containing benzyl alcohol as a preservative, typically 0.9 percent by volume. The preservative inhibits microbial growth, which extends the shelf life of the reconstituted peptide solution compared with sterile water. Pfizer’s labelling guidance for bacteriostatic water describes the product as sterile water for injection containing benzyl alcohol as a preservative.

A 10ml vial contains 10 millilitres of bacteriostatic water. This is enough for several reconstitutions, depending on the volume used per vial. The Alta Peptides bacteriostatic water product page lists the available configurations and documentation.

How the volume per reconstitution is determined

The volume of diluent added to a peptide vial determines the concentration of the resulting solution. The calculation is simple: the mass of peptide in the vial divided by the volume of diluent added.

Concentration (mg/mL) = Mass of peptide (mg) / Volume of diluent (mL)

For example, if a vial contains 10mg of peptide and 2ml of diluent is added, the concentration is 5mg/ml. If 1ml of diluent is added, the concentration is 10mg/ml.

Researchers choose the volume based on the concentration they need for their protocol. Some protocols call for a more concentrated solution, others for a more dilute one. The choice affects both the concentration and the number of reconstitutions a single bottle of bacteriostatic water can support.

How many reconstitutions a 10ml vial covers

The number of reconstitutions depends on the volume used per vial. Here is the calculation for common volumes.

These figures are theoretical maximums. In practice, a small amount of diluent is lost during each reconstitution due to the dead space in the syringe and the residue left in the bottle. A realistic estimate is 10 to 15 percent less than the theoretical maximum.

The Alta Peptides reconstitution calculator works out the concentration and the volume required for a given mass, which helps with planning the number of reconstitutions.

Choosing between 10ml and other sizes

Bacteriostatic water is available in several sizes. The 10ml size is a middle ground that suits most laboratory workflows. Smaller sizes, such as 5ml, are more appropriate for occasional use. Larger sizes, such as 30ml, are more economical per millilitre but need to be used within the shelf life of the preservative.

The shelf life of the opened bottle matters. Once the bottle is opened, the preservative continues to inhibit microbial growth, but its effectiveness declines over time. The Bachem handling and storage guidelines for peptides provide additional context on the storage conditions that maintain the integrity of the diluent and the reconstituted solution.

The Alta Peptides guide to lyophilised peptide stability explains how temperature and humidity affect the peptide powder and the reconstituted solution.

How Alta Peptides supplies bacteriostatic water

Alta Peptides supplies bacteriostatic water as part of its research accessories range. The company also supplies alcohol swabs for vial hygiene and insulin syringes for accurate measurement.

Common questions about bacteriostatic water 10ml

How many reconstitutions does a 10ml vial cover?

For typical reconstitutions using 1ml to 2ml per peptide vial, a 10ml bottle covers 5 to 10 reconstitutions. The exact figure depends on the volume used per vial, which is determined by the concentration you want to achieve.

How do I calculate the volume of diluent per reconstitution?

The concentration of the solution is the mass of peptide divided by the volume of diluent added. To achieve a target concentration, divide the mass by the target concentration to find the volume.

Should I choose a 10ml or a 30ml bottle?

The 10ml bottle suits most laboratory workflows. Larger bottles are more economical per millilitre but need to be used within the shelf life of the preservative. Smaller bottles, such as 5ml, are more appropriate for occasional use.

How should I store bacteriostatic water?

Bacteriostatic water should be stored according to the manufacturer’s instructions. The product should be kept sealed until use and stored at the recommended temperature. Once opened, the vial should be handled carefully to prevent contamination.

What is the difference between bacteriostatic water and sterile water?

Bacteriostatic water contains benzyl alcohol as a preservative. Sterile water contains no preservative. The preservative extends the shelf life of the solution after opening, but it may be contraindicated for certain applications.

How long is a reconstituted peptide solution stable?

The stability of a reconstituted solution depends on the peptide and the diluent. The GenScript storage guide recommends storing reconstituted peptides at 2 to 8 degrees Celsius and using them within a defined window. Bacteriostatic water extends the shelf life compared with sterile water.