This test reveals contamination by bacterial endotoxins (lipolysaccharide), which is a membrane component of gram-negative bacteria. This reaction is the basis of LAL test, used for detection and quantification of bacterial endotoxins. Limulus amebocyte lysate (LAL) is an aqueous extract of blood cells (amoebocytes) from the Atlantic horseshoe crab, Limulus polyphemus.
It was later recognized that the animal’s blood cells contain granules with a clotting factor known as coagulogen; this is released outside the cell when bacterial endotoxin is encountered. Resulting coagulation is thought to contain bacterial infections in the animal’s semi-closed circulatory system.
LAL reacts with bacterial endotoxin lipopolysaccharide (LPS).
Test for endotoxins is performed in compliance with Europe pharmacopeia test 2.6.14.