Peptide Lab HQ Research Guide
LL-37
A research-focused compound profile covering LL-37 identity, human cathelicidin peptide research, antimicrobial and antibiofilm models, epithelial-response research, wound-healing pathway context, concentration reference, reconstitution reference, and safety considerations.
Compound Data
Compound Profile
| Compound Name | LL-37 |
|---|---|
| Common Research Names | Human cathelicidin LL-37, hCAP-18-derived peptide, CAMP-derived peptide, cathelicidin antimicrobial peptide LL-37 |
| Compound Type | Human host-defense peptide / antimicrobial peptide / cathelicidin-derived research peptide |
| CAS Number | 154947-66-7; verify against supplier COA |
| PubChem CID | 16198951 |
| Amino Acid Length | 37 amino acids |
| Amino Acid Sequence | Leu-Leu-Gly-Asp-Phe-Phe-Arg-Lys-Ser-Lys-Glu-Lys-Ile-Gly-Lys-Glu-Phe-Lys-Arg-Ile-Val-Gln-Arg-Ile-Lys-Asp-Phe-Leu-Arg-Asn-Leu-Val-Pro-Arg-Thr-Glu-Ser |
| Short Sequence | LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES |
| Structural Feature | Cationic amphipathic peptide that can adopt alpha-helical structure in membrane-like environments |
| Molecular Formula | C₂₀₅H₃₄₀N₆₀O₅₃; verify against supplier COA |
| Molecular Weight | Approximately 4493.32 g/mol; verify against supplier COA |
| Research Category | Antimicrobial peptide research, antibiofilm models, epithelial repair, wound-healing pathway research, angiogenesis, immune modulation, inflammatory signaling, and host-defense peptide research |
| Research Context | Commonly discussed in controlled research involving bacterial membrane disruption, biofilm response, epithelial migration, wound closure, endothelial response, chemotaxis, innate immune signaling, and inflammatory disease models. |
| Appearance | White to off-white lyophilized powder, depending on supplier documentation |
| Use | For laboratory research use only. |
Reference Only
Reconstitution / Research Dosing Reference
Quick Reference Summary
| Reference Vial | 5 mg LL-37 |
|---|---|
| Primary Solution Volume | 2.0 mL bacteriostatic water |
| Primary Concentration | 2.5 mg/mL |
| Measurement Reference | On a U-100 syringe, 1 unit = 0.01 mL. |
| Amount per U-100 Unit | At 2.5 mg/mL, 1 unit equals 0.025 mg / 25 mcg LL-37. |
| Storage Reference | Refrigerate at 2–8°C / 35.6–46.4°F after reconstitution, protected from direct light. |
Reconstitution Steps
- Draw 2.0 mL bacteriostatic water using a sterile syringe for the main concentration reference shown below.
- Slowly add the BAC water down the side of the vial wall.
- Gently roll or swirl the vial until the material is completely dissolved. The solution should appear clear. Do not shake!
- Label with compound name, vial amount, concentration, solvent volume, preparation date, storage conditions, and handling notes.
- Store refrigerated at 2–8°C / 35.6–46.4°F, protected from direct light.
Published Research Context
| Reference Type | Reported Amount / Context | Research Notes |
|---|---|---|
| Compound Identity Reference | LL-37, human cathelicidin antimicrobial peptide | LL-37 is commonly identified as a 37-amino-acid human cathelicidin peptide associated with innate immune and antimicrobial peptide research. |
| Antimicrobial Research Context | Model-dependent concentration and endpoint tracking | Commonly discussed in antimicrobial peptide, bacterial membrane, biofilm, Gram-positive, Gram-negative, and host-defense peptide research contexts. |
| Innate Immune / Inflammatory-Marker Research | Neutrophil-response and cytokine-marker context | LL-37 has been discussed in research involving neutrophil activation, bacterial stimulation, cytokine release, reactive oxygen species, phagocytosis, and inflammatory-mediator response. |
| Wound-Healing / Angiogenesis Research | Experimental wound-regeneration and vascularization context | LL-37 has been studied in wound-model research involving vascularization, re-epithelialization, angiogenesis markers, and tissue-response documentation. |
| Barrier / Epithelial Research Context | Model-dependent epithelial and tissue-response research | Commonly discussed in epithelial defense, skin-barrier, mucosal-barrier, tissue-repair, and host-defense research contexts. |
| Public Protocol-Style Reference | Microgram-to-milligram reference examples | Public protocol-style references commonly describe LL-37 in microgram-to-milligram examples depending on the research model and preparation format. These are not clinical dosing standards. |
| Clinical / Research-Chemical Status | No universal research-chemical protocol established | Published study references, public protocol-style references, wellness protocols, or public dosing pages should not be treated as dosing instructions for research-chemical vial formats. |
Concentration Reference
| Vial Amount | Solution Volume | Final Concentration |
|---|---|---|
| 5 mg | 2.0 mL | 2.5 mg/mL |
Research Dosing Amount / Volume Reference
| Reference Amount | Volume at 2.5 mg/mL | U-100 Unit Reference | Approx. References per 5 mg Vial |
|---|---|---|---|
| 50 mcg | 0.02 mL | 2 units | 100 |
| 100 mcg | 0.04 mL | 4 units | 50 |
| 0.25 mg / 250 mcg | 0.10 mL | 10 units | 20 |
| 0.5 mg / 500 mcg | 0.20 mL | 20 units | 10 |
| 1 mg / 1000 mcg | 0.40 mL | 40 units | 5 |
| 2 mg / 2000 mcg | 0.80 mL | 80 units | 2.5 |
| 5 mg / 5000 mcg | 2.00 mL | 200 units | 1 |
Research Frequency / Amount Reference
| Research Window | Frequency | Reference Amount | Units / Volume Reference |
|---|---|---|---|
| Lower Microgram Reference | Calculation reference only | 50 mcg reference amount | 2 units / 0.02 mL |
| Standard Microgram Reference | Public protocol-style reference, not a clinical dosing standard | 100 mcg reference amount | 4 units / 0.04 mL |
| Low Milligram Conversion Example | Public protocol-style reference, not a clinical dosing standard | 250 mcg reference amount | 10 units / 0.10 mL |
| Mid-Range Conversion Example | Calculation reference only | 0.5 mg reference amount | 20 units / 0.20 mL |
| Upper Conversion Example | Calculation reference only | 1 mg reference amount | 40 units / 0.40 mL |
| Preparation-Level Conversion Example | Calculation reference only | 2 mg reference amount | 80 units / 0.80 mL |
| Full-Vial Preparation Reference | Preparation-level calculation reference | 5 mg reference amount | 200 units / 2.00 mL |
Common Research Windows
| Reference Window | Common Length | Research Notes |
|---|---|---|
| Cell-Culture / Antimicrobial Observation Window | 24–72 hours | May be used for bacterial-response, biofilm, inflammatory-marker, cytokine, neutrophil-response, or epithelial-marker documentation depending on the model. |
| Acute Observation Window | Single session to several days | Used for short-term antimicrobial response, inflammatory-marker comparison, ROS tracking, neutrophil-response observation, or early pathway documentation depending on the research design. |
| Short Research Window | 1–2 weeks | May be used for early controlled observation involving innate immune markers, epithelial-response, antimicrobial models, or wound-response endpoints. |
| Standard Protocol-Style Window | 2–4 weeks | Commonly used in public protocol-style references for structured observation and comparison across baseline and follow-up periods. |
| Extended Observation Window | 4–8 weeks | Used when longer documentation is needed for tissue-response, inflammatory-marker, angiogenesis, wound-model, or epithelial-barrier trend tracking. |
| Follow-Up / Washout | 1–4 weeks | Used to document post-study observations, marker return, delayed response patterns, or follow-up data depending on the research model. |
Research Note: These tables are provided for educational, research-planning, concentration, frequency-reference, and volume-reference purposes only. LL-37 is commonly discussed in cathelicidin, antimicrobial peptide, innate immune, inflammatory-marker, neutrophil-response, epithelial-barrier, wound-healing, angiogenesis, and host-defense research contexts. This reference uses a 5 mg vial reconstituted with 2.0 mL bacteriostatic water. Published study references and public protocol-style frequency references are not universal research-chemical dosing standards and should not be treated as dosing instructions for research-chemical vial formats. This information is not medical advice, dosing instruction, injectable-use guidance, or a recommendation for human or animal use.
Reference Only
Reconstitution / Research Dosing Reference
Reconstitution Steps
- Draw 2.0 mL bacteriostatic water using a sterile syringe for the main concentration reference shown below, only if supported by supplier documentation.
- Slowly add the BAC water down the side of the vial wall.
- Gently roll or swirl the vial until the powder is completely dissolved. The solution should appear clear. Do not shake!
- Label with compound name, vial amount, concentration, solvent volume, preparation date, storage conditions, and handling notes.
- Store according to supplier documentation, protected from heat, moisture, and direct light.
Published Research Context
| Reference Type | Reported Amount / Context | Research Notes |
|---|---|---|
| Compound Identity Reference | 37-amino-acid human cathelicidin peptide | LL-37 is the active human cathelicidin peptide derived from the hCAP-18 / CAMP precursor. |
| Antimicrobial / Antibiofilm Research | Model-dependent in-vitro exposure | Published reviews describe LL-37 activity against multiple Gram-positive and Gram-negative pathogens and biofilm-related models. |
| Biofilm Formation Research | Model-dependent in-vitro exposure | LL-37 has been reported to affect biofilm formation by reducing bacterial attachment and influencing quorum-sensing-related behavior. |
| Wound-Healing Research | Topical and model-dependent exposure | Published research describes LL-37 involvement in epithelial wound closure, angiogenesis, and wound-regeneration models. |
| Angiogenesis Research | Endothelial-cell and animal model context | LL-37 has been studied for endothelial-cell activation, proliferation, and vessel-like structure formation in angiogenesis research. |
| In-Vitro Antiviral Context | IC₅₀ reported around 4.74 µg/mL in a SARS-CoV-2 pseudovirion model | Product literature references LL-37 interaction with viral entry-related models; this should be treated as in-vitro research context only. |
| Safety / Limitation Context | Concentration- and model-dependent cytotoxicity | Reviews note limitations including proteolytic instability, cytotoxicity, hemolytic activity, host-cell effects, and inflammatory/autoimmune pathway concerns. |
Concentration Reference
| Vial Amount | Solution Volume | Final Concentration |
|---|---|---|
| 5 mg | 2.0 mL | 2.5 mg/mL |
| 5 mg | 3.0 mL | 1.67 mg/mL |
Research Dosing Amount / Volume Reference
| Reference Amount | Volume at 2.5 mg/mL | U-100 Unit Reference | Approx. References per 5 mg Vial |
|---|---|---|---|
| 50 mcg / 0.05 mg | 0.02 mL | 2 units | 100 |
| 100 mcg / 0.10 mg | 0.04 mL | 4 units | 50 |
| 250 mcg / 0.25 mg | 0.10 mL | 10 units | 20 |
| 500 mcg / 0.50 mg | 0.20 mL | 20 units | 10 |
| 1 mg / 1000 mcg | 0.40 mL | 40 units | 5 |
| 1.25 mg / 1250 mcg | 0.50 mL | 50 units | 4 |
| 2.5 mg / 2500 mcg | 1.00 mL | 100 units | 2 |
| 5 mg / 5000 mcg | 2.00 mL | 200 units | 1 |
Common Research Windows
| Reference Window | Common Length | Research Notes |
|---|---|---|
| Cell-Culture Observation Window | Minutes to 72 hours | Often used for antimicrobial activity, membrane response, cytokine signaling, epithelial migration, chemotaxis, or cell-viability observations. |
| Biofilm Research Window | 24–96 hours | Commonly used for bacterial attachment, biofilm formation, biofilm disruption, quorum-sensing context, and microbial-response documentation. |
| Short Wound-Healing Research Window | 3–14 days | May be used for early epithelial-response, wound-closure, angiogenesis, and tissue-response observations in controlled models. |
| Standard Research Window | 2–4 weeks | May be used for structured documentation of wound-healing, antimicrobial, epithelial, angiogenesis, or inflammatory-response observations. |
| Extended Observation Window | 4–8 weeks | May be used in longer tissue-response, chronic wound, inflammatory, or host-defense peptide research models requiring repeated observation. |
| Follow-Up / Washout | 1–4 weeks | Used to document post-study observations, marker return, inflammatory-response resolution, or follow-up data depending on the research model. |
Research Note: These tables are provided for educational, research-planning, concentration, and volume-reference purposes only. Published LL-37 research includes antimicrobial, antibiofilm, epithelial-response, wound-healing, angiogenesis, immune-modulation, and inflammatory-pathway contexts. The calculations above assume a 5 mg LL-37 vial reconstituted with 2.0 mL bacteriostatic water, creating a 2.5 mg/mL concentration reference; however, LL-37 solubility and solvent compatibility should be verified against supplier documentation before preparation. This information is not medical advice, dosing instruction, injectable-use guidance, or a recommendation for human or animal use.
Research Notes
Research Findings & Safety Notes
Research Findings
LL-37 is commonly discussed in research involving antimicrobial activity, antibiofilm response, epithelial migration, wound closure, angiogenesis, chemotaxis, TLR signaling, cytokine response, innate immune regulation, and host-defense peptide function.
Study Limitations
LL-37 research includes cell-culture studies, microbial models, wound-healing models, inflammatory disease research, and host-defense peptide reviews. Findings should be interpreted according to microbial strain, cell type, salt concentration, peptide concentration, exposure duration, and model design.
Safety Considerations
Research discussion should account for membrane activity, cytotoxicity, hemolytic potential, inflammatory and autoimmune pathway context, proteolytic instability, host-cell effects, peptide purity, sterility documentation, endotoxin risk, storage conditions, and qualified laboratory handling procedures.
Use Restriction
Not for human or animal consumption. Not intended to diagnose, treat, cure, or prevent any disease when discussed as a research-use material.
Related Supplies
Research Supplies
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Bacteriostatic Water
Commonly referenced in laboratory preparation workflows.
Research Syringes
Supply category for controlled laboratory research preparation.
Prep Supplies
Supporting supplies for clean handling, preparation, and documentation.
Lab Handling
Handling & Storage
Storage
Store materials according to product-specific requirements. Protect from excessive heat, moisture, and direct light.
After Reconstitution
Keep refrigerated after reconstitution unless otherwise specified by the product documentation.
Handling
Use appropriate laboratory PPE, clean handling practices, and qualified research procedures.
Documentation
Maintain batch details, COA records, preparation notes, and internal research documentation.