LL-37: Research overview, identity, and laboratory handling guide
8 min read · Research use only
Written and reviewed by BluGen Research Team · Editorial standards
Human cathelicidin antimicrobial peptide LL-37 (37 residues). Widely studied in vitro for membrane interaction and innate-immunity research. Lyophilized, ≥99% HPLC. Research use only. This guide covers identity, published research context, procurement checks, and storage — RUO only, no clinical claims.
What LL-37 is in published research
LL-37 is the only known cathelicidin in humans, generated by proteolytic processing of hCAP-18. The peptide has been extensively studied in vitro for amphipathic α-helical conformation, membrane interaction, and modulation of pattern-recognition receptors. Published research uses LL-37 as a reference peptide in innate-immunity, biofilm, and structure-activity studies.
Our LL-37 ships at ≥99% HPLC purity with mass-spectrometry identity verification. Net peptide content (excluding water and counter-ion mass) is reported on the certificate of analysis — important for accurate concentration calculations in MIC and binding-assay work.
Hold lyophilized vials at -20 °C in original packaging away from light. Reconstitute in lab-grade water or near-neutral buffer; LL-37 is amphipathic and labs report best stability when working volumes are aliquoted and frozen on first reconstitution. Avoid plastic containers known to adsorb cationic peptides without a carrier.
CoA covers identity (MS), purity (HPLC), and net-peptide content. Batch records by lot are available for compliance and audit retrieval.
The material class "Cathelicidin peptide (research)" helps procurement teams group LL-37 with related reference peptides during comparative studies.
Sequence and identity
LL-37 identity on the catalog: Common name: LL-37 / hCAP-18; Sequence: LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES; Length: 37 residues; Molecular weight: 4,493.3 g/mol; Net charge (pH 7): +6; Appearance: White lyophilized powder; Purity (HPLC): ≥ 99%; Solubility: Soluble in bacteriostatic water; near-neutral buffers preferred. Copy these into receiving and LIMS before reconstitution.
Mechanisms studied in published research
Mechanism-focused research on LL-37 is typically conducted in cell lines or biochemical preparations that express the relevant receptor or binding protein for its class.
Design controls that include scrambled-sequence or orthogonal-receptor negative controls when your protocol evaluates LL-37 pharmacology in vitro.
Report effect sizes with lot number and CoA reference so results can be reproduced if the same LL-37 SKU is reordered later.
Avoid extrapolating in vitro binding or signaling readouts to whole-organism outcomes; RUO materials are not qualified for clinical investigation.
Procurement and identity verification
Request the lot-specific CoA for LL-37 at receipt. Verify SKU, variant size if applicable, and identity mass before the lot enters general storage.
Compare HPLC purity to your internal minimum for the peptide family. File chromatogram excerpts when your QMS requires raw data.
Enter net peptide content from the CoA into inventory before calculating molarity for LL-37 working stocks.
Attach purchase order, packing list, and CoA in one audit folder per lot.
Storage and reconstitution
Store lyophilized LL-37 sealed at -20 °C protected from light unless the CoA states otherwise.
Reconstitute with bacteriostatic water or a buffer validated for your assay pH. Aliquot to limit freeze-thaw.
For oxidation-sensitive sequences in LL-37, minimize open-vial time at room temperature during weighing.
See our lyophilized storage guide for institution-scale SOP examples and aliquot labeling conventions.
Comparative reference points
Researchers comparing LL-37 with adjacent catalog references often evaluate the following SKUs in parallel plates:
Use matched reconstitution buffers and stock concentrations when running comparative binding or signaling assays.
Document reviewers should cross-link this guide with the product certificate of analysis and internal receiving SOP.
When publishing methods, cite lot number, SKU, reconstitution buffer, and stock concentration so external labs can interpret your figures.
Institutional procurement may require RUO acknowledgment at checkout; store that acknowledgment beside batch records for audits.
If assay results drift across quarters, compare storage logs and CoA revision before questioning sequence integrity.
Third-party summaries, when available, should be filed as supplements—not replacements—for CoA identity data.
Document reviewers should cross-link this guide with the product certificate of analysis and internal receiving SOP.
When publishing methods, cite lot number, SKU, reconstitution buffer, and stock concentration so external labs can interpret your figures.
Institutional procurement may require RUO acknowledgment at checkout; store that acknowledgment beside batch records for audits.
If assay results drift across quarters, compare storage logs and CoA revision before questioning sequence integrity.
Third-party summaries, when available, should be filed as supplements—not replacements—for CoA identity data.
Document reviewers should cross-link this guide with the product certificate of analysis and internal receiving SOP.
When publishing methods, cite lot number, SKU, reconstitution buffer, and stock concentration so external labs can interpret your figures.
Institutional procurement may require RUO acknowledgment at checkout; store that acknowledgment beside batch records for audits.
If assay results drift across quarters, compare storage logs and CoA revision before questioning sequence integrity.
Third-party summaries, when available, should be filed as supplements—not replacements—for CoA identity data.
Document reviewers should cross-link this guide with the product certificate of analysis and internal receiving SOP.
When publishing methods, cite lot number, SKU, reconstitution buffer, and stock concentration so external labs can interpret your figures.
Institutional procurement may require RUO acknowledgment at checkout; store that acknowledgment beside batch records for audits.
If assay results drift across quarters, compare storage logs and CoA revision before questioning sequence integrity.
Third-party summaries, when available, should be filed as supplements—not replacements—for CoA identity data.
Document reviewers should cross-link this guide with the product certificate of analysis and internal receiving SOP.
When publishing methods, cite lot number, SKU, reconstitution buffer, and stock concentration so external labs can interpret your figures.
Institutional procurement may require RUO acknowledgment at checkout; store that acknowledgment beside batch records for audits.
If assay results drift across quarters, compare storage logs and CoA revision before questioning sequence integrity.
Third-party summaries, when available, should be filed as supplements—not replacements—for CoA identity data.
Document reviewers should cross-link this guide with the product certificate of analysis and internal receiving SOP.
When publishing methods, cite lot number, SKU, reconstitution buffer, and stock concentration so external labs can interpret your figures.
Institutional procurement may require RUO acknowledgment at checkout; store that acknowledgment beside batch records for audits.
If assay results drift across quarters, compare storage logs and CoA revision before questioning sequence integrity.
Third-party summaries, when available, should be filed as supplements—not replacements—for CoA identity data.
Document reviewers should cross-link this guide with the product certificate of analysis and internal receiving SOP.
When publishing methods, cite lot number, SKU, reconstitution buffer, and stock concentration so external labs can interpret your figures.
Institutional procurement may require RUO acknowledgment at checkout; store that acknowledgment beside batch records for audits.
If assay results drift across quarters, compare storage logs and CoA revision before questioning sequence integrity.
Third-party summaries, when available, should be filed as supplements—not replacements—for CoA identity data.
Document reviewers should cross-link this guide with the product certificate of analysis and internal receiving SOP.
When publishing methods, cite lot number, SKU, reconstitution buffer, and stock concentration so external labs can interpret your figures.
Institutional procurement may require RUO acknowledgment at checkout; store that acknowledgment beside batch records for audits.
If assay results drift across quarters, compare storage logs and CoA revision before questioning sequence integrity.
Third-party summaries, when available, should be filed as supplements—not replacements—for CoA identity data.
Frequently asked questions
Is LL-37 for clinical programs?
No. It is sold for research use only (RUO) to qualified buyers.
What purity should we expect for LL-37?
Listings target ≥99% HPLC with MS identity on the lot CoA. Verify on receipt, not from marketing copy alone.
How do we calculate molarity for LL-37?
Use net peptide content from the CoA divided by molecular weight, then divide by reconstitution volume.
Can we mix lots of LL-37 in one stock?
Avoid mixing lots unless your protocol explicitly requires it. Mixed lots break traceability.
Where is the LL-37 product listing?
View the catalog PDP for LL-37 for variant SKUs and quote or purchase options.
Citation
BluGen Research Peptides — LL-37: Research overview, identity, and laboratory handling guide. https://getblugen.com/research/research-guide-ll-37/. Accessed 2026-06-14.
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