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How did Frederick Bang and Jack Levin contribute to the LAL test?

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Horseshoe crab (Limulus polyphemus) with a hard, rounded shell and long pointed tail lying on sandy ground. — horseshoe crab Horseshoe crab (*Limulus polyphemus*).

The contributions of Frederick Bang and Jack Levin were pivotal in the development of the Limulus amoebocyte lysate (LAL) test, a critical tool for ensuring medical safety.

In 1956, American scientist Frederick Bang discovered that the blood of the horseshoe crab contains a primitive clotting agent known as coagulogen. Building upon this discovery during the 1960s, American hematologist Jack Levin developed the LAL test to detect the presence of gram-negative bacteria in medical injections.1

When the LAL reagent comes into contact with gram-negative bacteria or endotoxin, the coagulogen reacts to form a clot, or "gel," even at extremely low concentrations. This rapid testing method, which was licensed in 1977, remains a vital safeguard for protecting patients from harmful contaminants in drugs, intravenous solutions, and medical instruments.1