Bacterial endotoxins test (BET)

A test that measures endotoxin, the fever-causing lipopolysaccharide from the outer membrane of Gram-negative bacteria, usually with Limulus amebocyte lysate by gel-clot, turbidimetric or chromogenic methods, or where accepted with recombinant factor C reagents. In the Japanese Pharmacopoeia it is General Test 4.01 Bacterial Endotoxins Test, harmonized internationally. Unlike sterility and bioburden tests, it detects a toxin that remains after the bacteria are dead. Method validation includes testing for interfering factors, and products prone to low endotoxin recovery need hold-time studies with spiked endotoxin.