ArticleTomasulo PA, Levin J, Murphy PA, Winkelstein JA.
J Lab Clin Med. 1977 Feb;89(2):308-15.
Tritiated endotoxins were prepared by three different methods. The biological activities of the tritiated endotoxins were determined by the Limulus amebocyte lysate assay, a rabbit pyrogen assay, and a complement-activation assay and were compared to native, unlabeled endotoxin. All three tritiated endotoxin preparations manifested adequate biological activity in each of the three assay systems, and all three assays ranked the biological activity of the different endotoxin preparations in the same order. Endotoxin tritiated by the Wilzbach procedure retained most of its biological activity and also had the highest specific radioactivity. The good correlation between the Limulus lysate, rabbit pyrogen, and complement-activation assays suggests that the same active site of the endotoxin molecule is identified by the three different assays.