RECONSTITUTION GUIDE
How Much BAC Water for LL-37?
Quick answer: Add 2 mL of bacteriostatic water to a 5 mg LL-37 vial. This yields a concentration of 2500 µg/mL. A standard 100 µg research dose then requires 0.04 mL (4 IU on a 100-unit insulin syringe).
Concentration by BAC water volume
Concentration and 100 µg draw volume at common BAC water volumes for a 5 mg vial.
| BAC water | Concentration | Dose volume | Draw |
|---|---|---|---|
| 1 mL | 5000 µg/mL | 0.02 mL | 2 IU |
| 2 mL Standard | 2500 µg/mL | 0.04 mL | 4 IU |
| 3 mL | 1666.67 µg/mL | 0.06 mL | 6 IU |
| 5 mL | 1000 µg/mL | 0.1 mL | 10 IU |
Dose volume at the standard 2500 µg/mL concentration
How draw volume changes if you vary the dose at the standard 5 mg + 2 mL reconstitution.
| Dose | Volume | IU draw (100u) |
|---|---|---|
| 50 µg | 0.02 mL | 2 IU |
| 100 µg Std | 0.04 mL | 4 IU |
| 150 µg | 0.06 mL | 6 IU |
| 200 µg | 0.08 mL | 8 IU |
| 300 µg | 0.12 mL | 12 IU |
Reconstitution steps
- Wipe the top of both the LL-37 vial and the bacteriostatic water vial with alcohol swabs.
- Draw 2 mL of bacteriostatic water into a sterile syringe.
- Inject the water slowly down the inside glass wall of the LL-37 vial. Do not aim directly at the powder.
- Swirl gently until fully dissolved. Never shake.
- Refrigerate at 2–8°C protected from light. Allow to reach room temperature before each draw.
Supplies needed
- LL-37 5 mg lyophilized vial
- 2 mL bacteriostatic water (0.9% benzyl alcohol)
- 100-unit (1 mL) U-100 insulin syringe
- Alcohol swabs
- Sharps container for disposal
Frequently asked
How much BAC water do I add to a 5 mg LL-37 vial?
For the standard ASCEND research protocol, add 2 mL of bacteriostatic water to a 5 mg LL-37 vial. This yields 2500 µg/mL.
What concentration does 2 mL BAC water give for 5 mg LL-37?
A 5 mg LL-37 vial reconstituted with 2 mL of bacteriostatic water yields 2500 µg/mL. A 100 µg dose then requires 0.04 mL (4 IU on a 100-unit insulin syringe).
Can I use sterile water instead of bacteriostatic water for LL-37?
Bacteriostatic water (0.9% benzyl alcohol) is preferred because it inhibits bacterial growth and allows multi-dose use of the reconstituted vial. Sterile water lacks preservative properties and accelerates peptide degradation once the vial is opened.
How long is LL-37 stable once reconstituted with BAC water?
Most research peptides remain stable for approximately 28 days when reconstituted with bacteriostatic water and stored at 2–8°C protected from light. Refer to peptide-specific stability data for any deviation from this baseline.
What size insulin syringe should I use for LL-37?
For a 100 µg dose (4 IU draw), a 30-unit (0.3 mL) U-100 insulin syringe gives the finest resolution. A 100-unit syringe also works.
Related
For research use only. Not medical advice. Consult a qualified healthcare provider before using any peptide compound. Reconstitution parameters cross-referenced with independent 3rd-party analytical laboratories. · ASCEND · ascendpeptide.org