Endotoxin

Lipopolysaccharide from the outer membrane of Gram-negative bacteria, released when cells die or divide. Endotoxin is heat-stable and pyrogenic: when injected, it causes fever and, at high doses, shock. It survives normal steam sterilisation, so it is controlled by preventing Gram-negative growth in water and materials and by depyrogenation. Parenteral products and WFI are tested for endotoxin using the bacterial endotoxin test.