LL-37 5mg

LL-37 is the 37-residue C-terminal peptide of hCAP-18, the only cathelicidin found in humans. It is an amphipathic, alpha-helical host-defence peptide named for its two N-terminal leucines. Contexx Research supplies LL-37 in Canada as a 5 mg lyophilized peptide for antimicrobial, membrane-biophysics and immunology research.

LL-37 specifications

Research overview

LL-37 is cleaved from its precursor by serine proteases and folds into an amphipathic helix when it meets lipid membranes. Dürr and colleagues’ 2006 review describes its structure, its membrane-disrupting mechanisms against bacteria and its broader role as an immune modulator [1].

Biophysical studies have described LL-37 as a pore-forming antibacterial peptide that also acts on host cells, modulating chemotaxis, cytokine release and receptor signalling through FPR2, P2X7 and EGFR [2]. Because of this dual role, it is studied in both microbiology and cell signalling.

LL-37 is also a template for antimicrobial peptide design. Wang and colleagues review how truncation, residue substitution and stabilisation of LL-37 fragments have produced shorter analogues with modified activity and selectivity [3]. Typical laboratory uses include MIC and biofilm assays, membrane-permeabilisation studies with model liposomes, and host-cell signalling experiments.

Selected references

1. Dürr UH et al. Biochim Biophys Acta. 2006. PubMed 16716248
2. Xhindoli D et al. Biochim Biophys Acta. 2016. PubMed 26556394
3. Wang G et al. Adv Exp Med Biol. 2019. PubMed 30980360

Storage and handling

LL-37 ships as a lyophilized (freeze-dried) powder. Dry material is far more stable than material in solution, so keep it in its dry, sealed state until you need it.

• Store unopened vials of LL-37 at −20 °C, dry and protected from light. Let the vial reach room temperature before opening to limit condensation.
• Prepare stock solutions in a solvent suited to your assay, label them with concentration and date, and keep them at 2–8 °C for short-term use.
• For longer storage of solutions, divide them into single-use aliquots and freeze them; avoid repeated freeze–thaw cycles.
• Handle with gloves and eye protection, following your laboratory’s standard chemical-hygiene practice.

See our guide to storing lyophilized peptides in the lab for more detail.

Quality and testing

Contexx Research independently tests every batch it releases. A lot-specific COA for LL-37 isn’t linked on this page yet. For questions about testing, contact info@contexxresearch.ca.

We don’t list purity figures in this description; the lot COA is the reference for identity and purity. Researchers should confirm identity and concentration with their own analytical methods where their protocol requires it.

Frequently asked questions

What’s included when I order LL-37 5 mg?

One sealed vial containing 5 mg of LL-37 as a lyophilized powder. Reconstitution solution is sold separately.

Does LL-37 come with a Certificate of Analysis (COA)?

Every batch Contexx Research releases is independently tested. A lot-specific COA isn’t linked on this page yet; for testing questions, contact info@contexxresearch.ca.

How fast is shipping in Canada?

Orders are processed Monday to Friday, and most orders ship within 24 hours from Mississauga, Ontario, in secure, tamper-evident packaging. Orders placed on Friday afternoon (after the 12:00 PM ET cut-off) ship on Monday, when Canada Post resumes pickup, or on the next business day if Monday is a statutory holiday. Once your order ships, delivery typically takes 1–3 business days in Ontario and Quebec and 2–6 business days in the rest of Canada, and a tracking number is emailed to you. Orders over $250 CAD shipped within Canada qualify for free standard shipping. See our Shipping Policy for details.

How should LL-37 be stored?

Store unopened vials at −20 °C, dry and protected from light. After reconstitution, keep solutions at 2–8 °C for short-term use, or freeze single-use aliquots and avoid repeated freeze–thaw cycles.

What does “research use only” mean?

“Research use only” means LL-37 is sold only as a reference material for in-vitro laboratory and analytical research by qualified professionals. It is not for use in humans or animals, not for diagnostic use, and not a drug, natural health product, food, supplement or cosmetic.

Research use only

LL-37 is sold by Contexx Research Inc. strictly as a reference material for in-vitro laboratory research and analytical use by qualified professionals. It is not a drug, natural health product, food, dietary supplement or cosmetic. It is not intended for use in humans or animals, for diagnostic purposes, or for ingestion or any other form of administration to a living organism. Nothing on this page describes or implies any effect in humans or animals. Purchasers are responsible for handling, storage and disposal in line with applicable laws and their institution’s policies. By ordering, you confirm that you are purchasing for legitimate laboratory research and agree to our Terms and Conditions.