Peptide Reconstitution
A quick step-by-step guide to reconstituting your research peptides safely and correctly.
Draw BAC water
- Pull air into syringe equal to desired BAC volume.
- Inject air into BAC vial.
- Invert vial and slowly draw water.
Add water to peptide
- Insert needle into peptide vial.
- Aim the stream against the glass wall, not directly onto powder.
- Inject slowly.
Shaking degrades the peptide. Always swirl gently.
Dissolve gently
- Gently swirl or roll vial between fingers.
- Powder should dissolve within 1–2 minutes.
- Solution should become clear.
- If cloudy or foamy → let it rest and gently swirl again.
❄️ Storage
- Store reconstituted peptides at 2–8°C (refrigerator)
- Keep away from light
- Do not freeze unless manufacturer states it’s acceptable
- Typical shelf life after reconstitution: 2–4 weeks (varies by peptide)
⚠️ Safety tips
- Use new sterile syringe for each draw.
- Never reuse needles or pipette tips.
- Discard if solution becomes cloudy, colored, or contains particles.
- Avoid touching needle or vial stopper.
🚩 Common mistakes to avoid
- Shaking the vial
- Using tap or distilled water instead of BAC water
- Forgetting to label preparation date and solvent
- Guessing doses instead of calculating properly
Reconstitution maths — quick reference
The concentration in mg/ml is simply vial strength ÷ water added. Pick your desired concentration first, then back-solve for the water volume.
| Vial strength | Water added | Concentration | Per 10 IU mark |
|---|---|---|---|
| 5 mg | 1 ml | 5 mg/ml | 500 mcg |
| 5 mg | 2 ml | 2.5 mg/ml | 250 mcg |
| 10 mg | 1 ml | 10 mg/ml | 1000 mcg |
| 10 mg | 2 ml | 5 mg/ml | 500 mcg |
| 10 mg | 5 ml | 2 mg/ml | 200 mcg |
| 30 mg | 3 ml | 10 mg/ml | 1000 mcg |
Sterile technique checklist
- Wash hands; work on a clean surface clear of papers and food.
- Wipe the vial septum and bacteriostatic-water stopper with a fresh alcohol swab; let them air-dry for 10 seconds before piercing.
- Use a new sterile syringe and needle for every withdrawal.
- Inject the water slowly down the inside wall of the vial — do not squirt directly onto the lyophilised cake; the force can denature the peptide.
- Swirl gently to dissolve; do not shake.
- Label the reconstituted vial with the date, concentration, and batch ID.
- Discard sharps in a labelled sharps container.
Common mistakes that wreck a batch
- Vigorous shaking. Peptides are easily denatured by mechanical shear. Always swirl, never shake.
- Wrong solvent. Use bacteriostatic water for multi-use vials. Plain saline can support bacterial growth; pure water can damage some peptides.
- Leaving the vial at room temperature after reconstitution. Once dissolved, all peptides need 2–8 °C storage — except very short windows during withdrawal.
- Re-using needles. Each reuse risks contamination and septum coring.
Frequently asked: reconstitution
How much water is right for a 10 mg vial?
It depends on your target concentration. 1 ml gives 10 mg/ml; 2 ml gives 5 mg/ml. Choose so each typical study dose corresponds to a convenient syringe-mark fraction.
Can I use plain saline instead of bacteriostatic water?
No — plain saline has no preservative and will support microbial growth across multiple withdrawals. Bacteriostatic water (0.9% benzyl alcohol) is the standard solvent for multi-use research vials.
Why did my peptide turn cloudy after mixing?
Cloudiness usually means the peptide has aggregated due to mechanical shear (shaking), pH stress, or repeated freeze-thaw. The batch should not be used. Email support with photos and the batch ID.