Limulus blood coagulation

Jack Levin, who had an interest in the effects of endotoxin on platelets and human blood coagulation, joined Bang at Woods Hole, MA, for several summers to do research on endotoxin-initiated Limulus blood coagulation. This collaboration produced several publications that explained a simple mechanism of enzyme-mediated interaction of LAL with endotoxin. " " Levin discovered a way to harvest the intracellular fluid by osmotic lysis of stabilized amebocytes. Modern-day preparation of LAL reagent still follows Levin s basic methods. 

Levin, J. Bang, F.B. The role of endotoxin in the extracellular coagulation of Limulus blood. Bull. Johns Hopkins 55. Hosp. 1964, 775 (3), 265-274. 

Development of the LAL assay was based upon the observation that the presence of Gramnegative bacteria in the vascular system of the American horseshoe crab, Limulus polyphemus, resulted in the clotting of its blood. Tests on fractionated blood showed that the factor responsible for coagulation resided within the crab s circulating blood cells, i.e. the amoebocytes. Further research revealed that the bacterial agent responsible of initiation of clot formation was endotoxin. 

Limulus Amebocyte Eysate (EAE) Test This test is used to detect the presence of endotoxins in the drug substance. It relies on the coagulation reaction between the endotoxin and the blood of a horseshoe crab. 

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