LL-37 For Sale — Research Grade
PX1 Research provides certified, analytical-grade LL-37 for sale to academic institutions, biotechnology labs, and research facilities nationwide. Synthesized in domestic, GMP-compliant facilities and verified by independent ISO 17025 accredited laboratories, our LL-37 cathelicidin peptide meets stringent purity standards for in vitro and preclinical experimentation. Orders placed Monday through Friday dispatch same-day from our dual distribution centers in California and Arizona.
Quick answer
PX1 Research provides certified, analytical-grade LL-37 for sale to academic institutions, biotechnology labs, and research facilities nationwide. Synthesized in domestic, GMP-compliant facilities and verified by independent ISO 17025 accredited laboratories, our LL-37 cathelicidin peptide meets stringent purity standards for in vitro and preclinical experimentation. Orders placed Monday through Friday dispatch same-day from our dual distribution centers in California and Arizona.
Key takeaways
- [LL-37](/research-peptides/ll-37) is the sole human representative of the cathelicidin family of antimicrobial host defense peptides.
- The primary primary sequence of [LL-37](/research-peptides/ll-37) (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) yields a net positive charge of +6 at physiological pH.
- To ensure reliable performance in sensitive analytical assays, PX1 Research subjects every lot of [LL-37](/research-peptides/ll-37) for sale to rigorous testing protocols.
- Because [LL-37](/research-peptides/ll-37) interacts directly with bacterial components such as lipopolysaccharides (LPS), exogenous endotoxin contamination in raw peptide preparations can severely invalidate experimental data.
Overview of LL-37 in Preclinical Research
LL-37 is the sole human representative of the cathelicidin family of antimicrobial host defense peptides. Originating from the cleavage of the hCAP18 precursor protein by proteinase 3, LL-37 consists of a 37-amino acid sequence rich in basic residues. In biological systems, this amphipathic alpha-helical structure allows the peptide to interact directly with anionic lipid membranes, making it a pivotal subject of study in innate immunology, cell signaling, and barrier function dynamics.
When evaluating options for sourcing high-purity compounds, researchers looking for LL-37 for sale require verified structural integrity and consistent sequence fidelity. In vitro assays routinely measure its secondary structure transitions, membrane permeabilization kinetics, and receptor binding affinities. Because slight chemical impurities or truncated peptide sequences can dramatically alter receptor interactions or surfactant properties, securing analytical-grade material is essential for reproducible experimental outcomes.
Molecular Structure and Receptor Interaction Profile
The primary primary sequence of LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) yields a net positive charge of +6 at physiological pH. This cationicity drives electrostatic attraction toward negatively charged bacterial cell membranes or mammalian cell surface microdomains. Structural studies using circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy show that while LL-37 remains largely unstructured in aqueous solution, it rapidly adopts a rigid alpha-helical conformation upon encountering lipid bilayers or trifluoroethanol (TFE) environments.
Beyond membrane interactions, preclinical studies indicate that LL-37 functions as a pleiotropic signaling ligand. It engages Formyl Peptide Receptor-like 1 (FPRL1/FPR2) to trigger downstream intracellular signaling cascades, including the MAPK/ERK and PI3K/Akt pathways. In cell culture models, these interactions influence leukocyte chemotaxis, keratinocyte migration, and angiogenesis. Investigating these receptor-mediated events requires reference-grade peptides supplied with high sequence fidelity.
Analytical Purity Standards and Quality Assurance
To ensure reliable performance in sensitive analytical assays, PX1 Research subjects every lot of LL-37 for sale to rigorous testing protocols. Primary identity and purity determinations are established using high-performance liquid chromatography (HPLC) paired with electrospray ionization mass spectrometry (ESI-MS). Each batch must meet or exceed a minimum HPLC purity threshold of 98.0%, confirming the absence of significant deletion sequences or synthesis side products.
Our analytical documentation includes complete chromatographic profiles with retention time verification, as well as mass-to-charge (m/z) spectrum analysis confirming the target molecular weight of 4493.3 Da. Researchers can review these metrics directly prior to project initiation via our open-access Certificate of Analysis (COA) repository accessible across our research peptides catalog.
Endotoxin Verification for Cellular and In Vitro Assays
Because LL-37 interacts directly with bacterial components such as lipopolysaccharides (LPS), exogenous endotoxin contamination in raw peptide preparations can severely invalidate experimental data. Endotoxin presence induces non-specific toll-like receptor (TLR4) activation in cell cultures, clouding observations related to cytokine modulation or cell survival.
PX1 Research conducts quantitative Chromogenic Limulus Amebocyte Lysate (LAL) testing on every lot of LL-37. We enforce strict endotoxin limits (<0.01 EU/mg) to ensure that observed cellular responses are attributable solely to the synthesized peptide sequence rather than residual bacterial pyrogens. This high level of quality control makes our material ideal for immunological research, cell migration assays, and microbial interaction studies.
Comparative Preclinical Profile: Host Defense and Tissue Repair Peptides
In experimental models evaluating barrier integrity, antimicrobial defense, and cellular remodeling, researchers often compare LL-37 to other signaling peptides across host defense and tissue repair categories. While LL-37 primarily acts as an amphipathic cathelicidin targeting membrane integrity and FPR2 signaling, peptides like KPV peptide exhibit distinct alpha-MSH-derived anti-inflammatory signaling without direct membrane-lytic properties. Similarly, BPC-157 peptide operates via distinct angiogenic and cytoprotective cascades, focusing on focal adhesion kinase activation rather than direct innate antimicrobial activity.
Furthermore, when investigating cell migration in epithelial models, scientists frequently compare LL-37 with Thymosin Beta-4, which regulates actin polymerization, or GHK-Cu, which modulates extracellular matrix gene expression. Understanding these distinct mechanistic pathways allows laboratory personnel to select the precise peptide candidate or multi-peptide model required for their specific in vitro research objective.
Primary In Vitro and Laboratory Application Areas
Research teams utilize high-purity LL-37 across several specialized laboratory domains. Key research areas include:
1. Antimicrobial Mechanics and Biofilm Disruption: In vitro assays evaluate the peptide's ability to disrupt pre-formed bacterial biofilms and permeabilize inner and outer bacterial membranes via carpet or toroidal pore mechanisms. 2. Epithelial Barrier Dynamics: Cell culture models utilize LL-37 to study tight junction protein expression (such as ZO-1 and occludin) in airway and intestinal epithelial monolayers. 3. Chemotaxis and Cell Migration: Assays measuring transwell leukocyte or keratinocyte migration evaluate FPR2 receptor activation and downstream cytoskeletal reorganization. 4. Lipopolysaccharide Neutralization: In vitro binding studies analyze how LL-37 sequesters free LPS, preventing TLR4 activation in macrophage cell lines.
Handling, Storage, and Reconstitution Protocols for Laboratory Use
LL-37 is supplied as a lyophilized (freeze-dried) powder under inert argon gas atmosphere to maintain long-term chemical stability. Upon arrival, unopened vials should be stored in a freezer at -20°C or -80°C, protected from light and moisture. Lyophilized peptides remain stable under these conditions for up to 24 months.
For laboratory reconstitution, researchers should allow the vial to equilibrate to room temperature before opening to prevent condensation. Reconstitution should be performed using sterile, endotoxin-free water or sterile phosphate-buffered saline (PBS, pH 7.4). Due to the cationic and amphipathic nature of LL-37, mild vortexing or gentle sonication may be utilized to achieve complete dissolution. Avoid vigorous agitation to prevent foam formation and peptide aggregation. Reconstituted stock solutions should be aliquoted into single-use microcentrifuge tubes and stored at -80°C to minimize freeze-thaw cycles.
PX1 Research Supply Chain and Fulfillment Standards
Securing a consistent supply of analytical-grade material is vital for maintaining project timelines and research integrity. PX1 Research manufactures all research compounds strictly in domestic, state-of-the-art facilities operating under current Good Manufacturing Practice (cGMP) guidelines. Our ISO 17025 accredited quality control framework guarantees lot-to-lot consistency across every product batch.
To support urgent laboratory timelines, all orders for LL-37 placed before cut-off time, Monday through Friday, ship the same day. Utilizing strategically located fulfillment hubs in California and Arizona, we offer rapid, temperature-monitored domestic transit options. Principal investigators and procurement managers seeking ongoing supply solutions or bulk pricing arrangements can register through our dedicated wholesale accounts portal.
Frequently Asked Questions
What is the certified purity level of LL-37 for sale at PX1 Research?
Every batch of LL-37 for sale from PX1 Research is verified by HPLC and ESI-MS to meet or exceed a minimum purity threshold of 98.0%.
How can researchers verify the analytical quality of their specific LL-37 lot?
Each shipment is linked to a lot-specific Certificate of Analysis (COA) containing raw HPLC chromatograms, mass spectrometry reports, and quantitative endotoxin test results.
Why is low endotoxin content critical when selecting LL-37 for in vitro studies?
Because LL-37 naturally interacts with LPS and immune receptors, background endotoxin contamination can trigger non-specific TLR4 activation, skewing cell culture data and cytokine quantification.
What molecular targets are studied using LL-37 in laboratory research?
LL-37 is widely studied for its binding affinity to Formyl Peptide Receptor-like 1 (FPRL1/FPR2), anionic bacterial membrane lipids, and circulating lipopolysaccharides (LPS).
How does LL-37 compare to other host defense or repair peptides?
Unlike smaller anti-inflammatory tripeptides like KPV or extracellular matrix repair peptides like BPC-157, LL-37 is an amphipathic 37-amino acid cathelicidin capable of both direct membrane disruption and FPR2 receptor signaling.
What solvent is recommended for reconstituting lyophilized LL-37?
Lyophilized LL-37 should be reconstituted using sterile, endotoxin-free water or sterile phosphate-buffered saline (PBS, pH 7.4) under aseptic laboratory conditions.
What are the proper storage conditions for LL-37 prior to reconstitution?
Unopened, lyophilized LL-37 should be stored at -20°C or -80°C in a dry environment protected from light. Under these conditions, the powder remains stable for up to 24 months.
What is the shipping schedule for LL-37 orders placed with PX1 Research?
Orders placed Monday through Friday before cut-off time ship the same day from our logistics facilities in California and Arizona.
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.