How to Mix Peptides
Peptides usually arrive as a dry powder. Mixing means adding water so the contents can be measured as a liquid.
Add bacteriostatic water to the dry powder, down the side of the vial, then swirl gently until clear. Researchers commonly use 2 to 3 mL of water for a 10 mg vial.
What You Need
- A lyophilised (freeze-dried) peptide vial
- Bacteriostatic water, the usual choice for a vial that will be opened more than once
- A sterile syringe with a needle
- Alcohol wipes
- A label and a pen
How Much Water to Add
The amount of water does not change how much peptide is in the vial. It changes the strength of the liquid. More water gives a weaker liquid and a larger draw. Less water gives a stronger liquid and a smaller draw.
Researchers commonly use 1 to 5 mL, depending on the size of the vial. Common practice
| Vial | Water Commonly Used | Resulting Strength |
|---|---|---|
| 5 mg | 1–2 mL | 2.5–5 mg/mL |
| 10 mg | 2–3 mL | 3.3–5 mg/mL |
| 15–20 mg | 3–5 mL | 3–6.7 mg/mL |
A useful check is the size of the draw. Researchers usually aim for 5 to 50 units on a U-100 syringe. Below 5 units the mark is hard to read. Above 50 a larger syringe is usual. Common practice The calculator checks this automatically.
The Seven Steps
Let the Vial Warm Up
Take the vial out of the fridge about 20 minutes before opening, so it reaches room temperature.
Wipe the Stoppers
Remove the flip-off caps. Wipe both rubber stoppers with an alcohol wipe and let them dry.
Draw the Water
Draw the volume of water chosen above into the syringe.
Add It Down the Side
Tilt the vial. Run the water slowly down the inner wall, not onto the powder.
Water aimed at the powder causes foam and slow dissolving.Swirl Gently
Swirl the vial gently until the powder dissolves. This can take a few minutes.
Shaking can damage the peptide, so swirl instead.Check the Liquid
The liquid should be clear. If it is cloudy, leave it at room temperature a little longer. If it stays cloudy or has particles, see when to throw it away.
Label the Vial
Write the compound, the strength and the date mixed on the vial.
These steps follow common practice among researchers. Common practice For a specific peptide, the supplier's data sheet comes first.
Check the Numbers
Enter the vial mass, the water volume and the target amount in the calculator. It returns the strength, the draw volume and the syringe reading, with the working shown.
After Mixing
Mixed liquid is commonly kept at 2–8 °C and away from light. The supplier's data sheet gives the time limit. Common practice The storage guide shows the powder and the liquid side by side.
Example: A Researcher Mixing a Vial
This video shows a researcher mixing a vial the way it is commonly done. Common practice
Third-party video: Peptide Reconstitution Instructions on YouTube. Where it differs from the supplier's data sheet, the data sheet wins.