The effects of /sup 60/Co irradiation performed with various doses on the biological and chemical properties of the endotoxin of the Salmonella minnesota R595 were compared with those of unirradiated ones. The biological activity was measured using the lethal toxicity test, the local Schwartzman reaction and by activating the complementary system. Increasing the irradiation dose from 50 to 200 kGy the preparation became less active in the biological tests but the protective activity against the lethal action of the endotoxin remained uneffected. The irradiation resulted in a dose-dependent decrease of the amounts of 2-keto-3-deoxy-octonate, glucosamine, fatty acids, but did not affect all the degradation products identified. Therefore, no correlation between the chemical composition and the absence of endotoxin activity was found.
El Sabbagh, M; Galanos, C; Luederitz, O;  Bertok, L;  Fuest, Gy 
- Max-Planck-Institut fuer Immunbiologie, Freiburg (Germany, F.R.)
- Orszagos Frederic Joliot-Curie Sugarbiologiai es Sugaregeszseguegyi Kutato Intezet, Budapest (Hungary)
- Orszagos Haema--tologiai es Vertranszfuzios Intezet, Budapest (Hungary)