What purity should LL-37 have?
Understanding purity standards for LL-37 in research settings: what 99%+ HPLC means, how to read a COA, and why purity matters for experimental results.
The research-grade purity standard
For research-grade peptides like LL-37, the gold standard is 99%+ HPLC-verified purity. HPLC (high-performance liquid chromatography) separates a peptide sample into its component molecules and measures the relative proportion of the target peptide versus any impurities, degradation products, or by-products from synthesis.
A 99%+ result means that less than 1% of the sample by mass is anything other than the target LL-37 molecule. For experimental reproducibility, anything below 95% introduces significant uncertainty — your results may be influenced by impurities rather than the peptide itself.
How to read a Certificate of Analysis (COA)
A real COA for LL-37 should contain:
- HPLC chromatogram — a visual trace showing peaks that correspond to the peptide's retention time
- Purity percentage — a specific number (e.g. 99.3%) derived from integrating the chromatogram
- Mass spectrometry confirmation — a molecular-weight reading matching the theoretical mass of LL-37
- Batch/lot number — tied to a specific manufacturing run
- Testing lab + date — independent third party, not self-certified
- Expiry date — based on stability studies for the compound
If any of these are missing, you cannot rely on the purity claim. Every Peptify COA includes all of the above and is downloadable from the product page.
Why impurities matter in research
Even small amounts of impurities in a research peptide can bind to unintended targets, trigger off-target effects in cell culture, or confound measurement assays. For quantitative research (dose-response curves, binding kinetics, concentration-dependent effects), using a <99% pure peptide can invalidate your data entirely.
Buy LL-37 for research
99%+ HPLC-verified LL-37 in stock. Every vial ships from the UK with a batch-specific Certificate of Analysis. Same-day dispatch on orders before 1pm.
Frequently asked questions
What is LL-37?
LL-37 is the only cathelicidin-derived antimicrobial peptide found in humans. It is studied in the antimicrobial, immune-modulation, and epithelial-barrier research literature.
What is LL-37 researched for?
Published preclinical research has examined LL-37 in antimicrobial-pathway, immune-signalling, and epithelial-barrier studies. It is one of the most-studied endogenous host-defence peptides in the in-vitro literature.
What purity does Peptify LL-37 meet?
Peptify LL-37 is 99%+ HPLC-verified with a batch-specific Janoshik Analytical Certificate of Analysis downloadable from the product page.