Endotoxin
Bacterial contaminants that cause fever and inflammation; tested via the LAL assay.
Definition
Lipopolysaccharide (LPS) molecules from gram-negative bacteria cell walls. Endotoxin contamination in peptides is detected using the LAL (Limulus Amebocyte Lysate) assay and can cause fever and inflammation. ACS offers quantitative endotoxin testing via LAL assay alongside heavy metal and residual solvent screening.
In More Detail
Endotoxins are heat-stable lipopolysaccharide molecules shed by gram-negative bacteria. Even when bacteria are killed during sterilization, the endotoxin fragments remain biologically active and can trigger fever, inflammation, and septic shock if injected. The Limulus Amebocyte Lysate (LAL) assay is the FDA-recognized method to quantify endotoxin in EU/mL or EU/mg. Pharmaceutical-grade peptides intended for injection typically need to fall below regulatory thresholds based on dose and route of administration.