New test for endotoxin potency based upon histamine sensitization in mice.

test(HHT) correlated wellwiththoseoftheothertwotests. Thesensitivity oftheHHT was aboutthesame as thatoftheCELD5o assay.TheHHT may provide a relatively inexpensive, fast, andreliable assaymethodforendotoxin laboratories thatdonothavethefacilities forthemore elaborate assays. Theidentification andquantitation ofendotoxin isalmost wholly dependent ontheeffects itproduces inbiological systems, because chemical analyses donotgive anymeasure ofendotoxic potency. Mostofthebioassays incommon useareexpensive and/or timeconsuming. Endotoxins, insub-microgram doses, fromgram-negative bacteria will induce atransient histamine hypersensitivity inmice(2). Thisobservation ledustotest this ability ofendotoxin asaquick, simple, andreasonably inexpensive methodfor detecting andquantitating endotoxin. Forthis purpose, wetested theability ofanumberof biological preparations toinduce histamine hypersensitivity inmiceandcompared theseresults withthose obtained fromotherbioassays forendotoxin potency, i.e., therabbit pyrogenicity andchicken embryolethality (CELD50) tests.