Determination of free lipid A and endotoxin (Abstract)
The wide spectrum of endotoxic activities among the different lipopolysac-charides has been shown recently to reside in the similar antigenic lipid A structure, which is an ubiquitous moiety in bacterial endotoxins (lipo-polysaccharides). Based upon this concept, a heterogeneous enzyme-immunoassay to first determine free lipid A has been set up. Different antisera were obtained from rabbits and goats immunized with lipid A vaccine. The specificity of anti-lipid A IgG antibodies obtained after ammonium sulphate precipitation and DEAE-A-50 chromatography was assayed by passive haemolysis inhibition test.