What is LL-37?
LL-37 is the only cathelicidin antimicrobial peptide found in humans. This 37-amino acid peptide (starting with two leucines, hence “LL”) is part of the innate immune system, providing first-line defense against pathogens.
Beyond direct antimicrobial activity, LL-37 modulates immune responses, promotes wound healing, and has anti-biofilm properties. It’s a key research target for antibiotic-resistant infections.
The 10mg vial provides an extended supply for longer research protocols, though the reconstituted stability window still applies.
Quick Reference
| Parameter | Value |
|---|---|
| Peptide Amount | 10mg |
| Recommended BAC Water | 4mL |
| Resulting Concentration | 2.5mg/mL |
| Typical Research Dose | 50-100mcg |
| Frequency | Once daily |
| Research Duration | 2-4 weeks |
Reconstitution Guide
Concentration Calculations
With 10mg in 4mL BAC water:
- Concentration: 2.5mg/mL = 2500mcg/mL
- Per unit (U-100): 25mcg per unit
Using 4mL rather than a smaller volume keeps the working concentration low enough that 50-100mcg doses land on readable syringe marks instead of fractions of a unit.
Dosage Protocol
Common Dose Calculations
| Desired Dose | Draw Volume | Syringe Units |
|---|---|---|
| 50mcg | 0.02mL | 2 units |
| 75mcg | 0.03mL | 3 units |
| 100mcg | 0.04mL | 4 units |
Doses Per Vial
| Dose | Doses | Duration |
|---|---|---|
| 50mcg | 200 doses | 200 days |
| 100mcg | 100 doses | 100 days |
The vial contains far more material than a single reconstituted batch will stay stable for, so plan around the 2-3 week window rather than the total dose count.
Suggested Protocol
- Dose: 50-100mcg
- Frequency: Once daily
- Duration: 2-4 weeks
Storage Requirements
| Form | Temperature | Duration |
|---|---|---|
| Lyophilized | -20°C | 2+ years |
| Reconstituted | 2-8°C | 2-3 weeks |
Note: LL-37 is sensitive. Use within 2-3 weeks.
Research Considerations
Mechanism of Action
- Direct antimicrobial — Membrane disruption
- Anti-biofilm — Prevents/disrupts biofilms
- Immunomodulation — Cytokine regulation
- Wound healing — Promotes repair
- Chemotaxis — Recruits immune cells
Research Areas
- Antibiotic-resistant infections
- Biofilm-associated infections
- Wound healing
- Immune modulation
- Skin conditions
Antimicrobial Spectrum
LL-37 has activity against:
- Gram-positive bacteria
- Gram-negative bacteria
- Fungi
- Some viruses
- Biofilm formations
Sourcing for Research
Source from verified suppliers that provide third-party testing and certificates of analysis (COA) for each batch. Compare purity documentation, shipping conditions, and batch traceability before purchasing research materials.