LAL test
Limulus amebocyte lysate assay — the standard method for quantifying bacterial endotoxin contamination.
For laboratory and research use only — not for human consumption.
The LAL test exploits the clotting response of horseshoe-crab blood cells (amoebocytes) to lipopolysaccharide. Three formats exist: gel-clot (qualitative or semi-quantitative), turbidimetric (kinetic, broad range), and chromogenic (kinetic, most sensitive). Results are reported in endotoxin units per millilitre (EU/mL); the European Pharmacopoeia accepts the recombinant Factor C (rFC) assay as an animal-free alternative. Research peptide suppliers routinely include an LAL or rFC endotoxin result on each batch's Certificate of Analysis.