How was the horseshoe crab test discovered?
In the 1960’s, Dr. Frederik Bang, a Johns Hopkins researcher working at the Marine Biological Laboratory in Woods Hole, Massachusetts, found that when common marine bacteria were injected into the bloodstream of the North American horseshoe crab, Limulus polyphemus, massive clotting occurred. Later, with the collaboration of Dr. Jack Levin, the MBL team showed that the clotting was due to endotoxin, a component of the marine bacteria originally used by Dr. Bang. In addition, these investigators were able to localize the clotting phenomenon to the blood cells, amebocytes, of the horseshoe crab, and, more importantly, to demonstrate the clotting reaction in a test tube. The cell-free reagent that resulted was named Limulus amebocyte lysate, or LAL. The name LAL is extremely descriptive: Limulus is the generic name of the horseshoe crab, amebocyte is the blood cell that contains the active components of the reagent, and lysate describes the original process used by Levin and Bang to obtai
