Buy LL-37 — USA-Made, COA per Lot
LL-37 is a widely studied 37-amino-acid cathelicidin-derived antimicrobial peptide utilized in preclinical models of innate immune response, membrane lysis, and cellular signaling. PX1 Research provides laboratory-grade LL-37 synthesized under strict domestic quality controls, verified by lot-specific third-party HPLC and mass spectrometry analysis. Every order ships same-day Monday through Friday from our fulfillment hubs in California and Arizona to support uninterrupted research workflows.
Quick answer
LL-37 is a widely studied 37-amino-acid cathelicidin-derived antimicrobial peptide utilized in preclinical models of innate immune response, membrane lysis, and cellular signaling. PX1 Research provides laboratory-grade LL-37 synthesized under strict domestic quality controls, verified by lot-specific third-party HPLC and mass spectrometry analysis. Every order ships same-day Monday through Friday from our fulfillment hubs in California and Arizona to support uninterrupted research workflows.
Key takeaways
- [LL-37](/research-peptides/ll-37) is the sole human representative of the cathelicidin family of antimicrobial peptides (AMPs).
- Procuring research peptides from unverified overseas vendors presents significant obstacles to experimental rigor.
- PX1 Research enforces stringent manufacturing and quality assurance protocols designed specifically for institutional and academic research facilities.
- In vitro data indicate that [LL-37](/research-peptides/ll-37) exerts broad-spectrum activity against Gram-positive and Gram-negative bacterial isolates through membrane permeabilization.
Introduction to LL-37 in Laboratory Research
LL-37 is the sole human representative of the cathelicidin family of antimicrobial peptides (AMPs). Cleaved from the C-terminal end of the hCAP18 proprotein, LL-37 consists of a 37-residue amphipathic alpha-helical structure characterized by a net positive charge at physiological pH. In biological systems, this cationic nature facilitates direct electrostatically driven interactions with negatively charged phospholipid bilayers, such as those found on bacterial outer membranes.
Investigators across microbiology, immunology, and cell biology utilize LL-37 research peptides to investigate mechanisms of innate immunity, bacterial membrane disruption, lipopolysaccharide (LPS) neutralization, and chemokine receptor transactivation. Because subtle sequence modifications or synthetic impurities can dramatically alter amphipathicity and biological activity, obtaining characterized, high-purity material is essential for reproducible experimental outcomes.
The Risks of Impure LL-37 Sourcing from Overseas Suppliers
Procuring research peptides from unverified overseas vendors presents significant obstacles to experimental rigor. Global gray-market suppliers frequently supply peptides with listed purities based on raw, unrefined HPLC profiles, omitting critical data regarding truncated side-products, residual TFA salts, heavy metal contamination, and bacterial endotoxins.
In cell culture assays and biochemical studies, high levels of background lipopolysaccharide (LPS) or endotoxins invalidate immunological data by triggering non-specific Toll-like receptor (TLR) activation. When primary macrophage or endothelial cell cultures are exposed to poorly purified peptides containing residual endotoxins, researchers risk recording false-positive inflammatory responses. Furthermore, overseas shipments often endure extreme thermal variation, prolonged transit delays, and customs seizures, compromising peptide stability before arrival at the laboratory.
PX1 Research Quality Advantage: USA Synthesis & ISO 17025 Verification
PX1 Research enforces stringent manufacturing and quality assurance protocols designed specifically for institutional and academic research facilities. All sequence production is carried out in domestic, GMP-compliant facilities adhering to solid-phase peptide synthesis (SPPS) standards. This approach yields precise amino acid sequence assembly while minimizing sequence deletion fragments.
Following synthesis, every batch undergoes independent analytical evaluation at an ISO 17025 accredited laboratory. Purity is confirmed via High-Performance Liquid Chromatography (HPLC), structural identity is validated through Electrospray Ionization Mass Spectrometry (ESI-MS), and endotoxin thresholds are quantitatively measured using Limulus Amebocyte Lysate (LAL) assays. Investigators can review full analytical documentation by visiting our research library hub, ensuring total transparency prior to assay deployment.
Preclinical Mechanisms and In Vitro Research Applications
In vitro data indicate that LL-37 exerts broad-spectrum activity against Gram-positive and Gram-negative bacterial isolates through membrane permeabilization. Preclinical models demonstrate that the peptide aligns along the lipid bilayer interface, inducing pore formation via carpet-like or toroidal pore mechanisms once a critical peptide-to-lipid ratio is achieved. This structural disruption destabilizes the bacterial transmembrane potential, leading to cytoplasmic leakage.
Beyond direct bactericidal pathways, research in non-human primate and rodent models suggests that LL-37 modulates host cellular signaling. The peptide binds extracellular LPS, preventing its interaction with TLR4/MD-2 complexes, and interacts with formyl peptide receptor-like 1 (FPRL1/FPR2) to induce chemotaxis in monocytes, neutrophils, and T-cells. Additionally, preclinical wound healing models highlight LL-37's involvement in promoting vascular endothelial growth factor (VEGF) expression and epithelial cell migration.
Comparative Analysis: LL-37 and Related Research Peptides
When evaluating compounds involved in tissue remodeling, barrier function, and innate host defense, researchers frequently compare LL-37 to other regulatory peptides. While LL-37 functions primarily via amphipathic membrane disruption and chemokine receptor transactivation, compounds like BPC-157 operate through distinct angiogenic and nitric oxide signaling pathways in preclinical gastrointestinal models. Similarly, TB-500 acts as an actin-sequestering agent focused on cell migration and cytoskeletal organization rather than direct antimicrobial action.
In assays exploring mucosal immunity and inflammatory modulation, researchers often pair or compare LL-37 with KPV peptide, an alpha-MSH derivative known for suppressive effects on NF-kB activation. Examining these distinct peptides within the broader umbrella of antimicrobial research peptides allows laboratories to isolate specific host defense pathways from general tissue repair mechanisms.
Analytical Verification: HPLC, Mass Spectrometry, and Endotoxin Testing
To guarantee experimental consistency, PX1 Research includes a lot-specific Certificate of Analysis (COA) with every order. The COA provides tangible proof of sequence integrity and chemical purity through three core analytical methodologies:
1. High-Performance Liquid Chromatography (HPLC): Establishes chemical purity, confirming that the target peptide constitutes >98% of the total UV absorbance profile at 214 nm and 220 nm. 2. Mass Spectrometry (MS): Confirms the exact molecular weight of the 37-amino-acid chain (theoretical MW ~4493.3 Da), eliminating the possibility of truncated fragments or incorrect sequence assembly. 3. LAL Endotoxin Testing: Quantifies bacterial endotoxin levels to ensure values remain well below established thresholds (<0.01 EU/mg), preventing non-specific immune cell activation during cell culture assays.
Laboratory Reconstitution and Handling Guidelines
LL-37 is supplied as a lyophilized, sterile-filtered powder to preserve peptide bond stability during transport. Lyophilized peptides should be stored upon receipt at -20°C in a dry environment shielded from light. Prior to opening the vial, allow the container to equilibrate to room temperature to prevent condensation of atmospheric moisture onto the lyophilized cake.
For reconstitution, use sterile bacteriostatic water or sterile phosphate-buffered saline (PBS, pH 7.4), depending on the requirements of your specific assay. If dissolving in aqueous buffer proves challenging due to hydrophobic interactions along the amphipathic helix, brief sonication or the addition of a dilute acetic acid solution (0.1%) can assist solubilization. Reconstituted aliquots should be frozen at -80°C to minimize freeze-thaw cycles and prevent structural degradation.
Fast Domestic Fulfillment & Secure Procurement Options
Research timelines require dependable supply chains. PX1 Research operates strategically located fulfillment centers in California and Arizona, allowing us to process and dispatch orders received before 3:00 PM EST on the same day, Monday through Friday. Domestic transit times typically range from 1 to 3 business days, eliminating the extended delays and customs clearance risks associated with international shipping.
For academic departments, contract research organizations (CROs), and corporate research facilities requiring bulk quantities or dedicated lot reservations, PX1 offers streamlined purchasing through our wholesale laboratory account portal. Institutional buyers receive dedicated account management, bulk pricing tiers, and advance lot reservation to guarantee continuity across longitudinal studies.
Frequently Asked Questions
What is the purity level of PX1 Research LL-37?
PX1 Research supplies LL-37 with a verified chemical purity of 98% or higher, as determined by High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS).
How is endotoxin contamination controlled in your LL-37 batches?
Every lot of LL-37 undergoes quantitative Limulus Amebocyte Lysate (LAL) endotoxin testing. We guarantee endotoxin levels below standard research thresholds (<0.01 EU/mg) to prevent non-specific TLR activation in cell-based assays.
Where are PX1 Research peptides synthesized and shipped from?
All PX1 Research peptides are synthesized in domestic, GMP-compliant facilities in the United States and shipped directly from fulfillment hubs in California and Arizona.
Can I obtain a lot-specific Certificate of Analysis (COA) for my order?
Yes. Every shipment includes access to a lot-specific COA containing full HPLC chromatograms, mass spectrometry reports, and LAL endotoxin test results.
What is the recommended solvent for reconstituting LL-37 in the lab?
LL-37 is typically reconstituted in sterile research-grade water or sterile PBS (pH 7.4). For difficult solutions, a 0.1% dilute acetic acid solution or mild sonication may be utilized to aid complete dissolution.
How should lyophilized LL-37 be stored upon arrival?
Lyophilized LL-37 should be stored at -20°C or -80°C in a desiccated container away from light. Reconstituted liquid aliquots should be stored at -80°C to avoid multiple freeze-thaw cycles.
What biological receptors does LL-37 target in preclinical models?
In vitro and animal models show that LL-37 interacts with formyl peptide receptor-like 1 (FPRL1/FPR2), P2X7 purinergic receptors, and neutralizes bacterial lipopolysaccharide (LPS) by binding directly to lipid A.
What is the molecular weight and sequence length of LL-37?
LL-37 is a 37-amino-acid peptide with a theoretical molecular weight of approximately 4493.3 Da.
Does PX1 Research offer institutional discounts for bulk LL-37 orders?
Yes, university labs, CROs, and corporate research programs can apply for a wholesale laboratory account to access volume pricing and lot-reservation options.
All products are sold strictly for laboratory and research use only. Not for human or veterinary use, diagnosis, treatment or consumption. Statements have not been evaluated by the FDA.