Lectins and lipopolysaccharides as linking agents for the red cell linked antigen test

Abstract

Lectins from the seeds of Euonymus europeaus and Dolichos biflorus as well as lipopolysaccharides from enterobacteria, have been used for linking proteins to red cells as a means of detecting antibody. Bovine serum albumin, human serum albumin, rabbit IgA, Salmonella adelaide, flagellin, and tetanus and diphtheria toxoids were covalently coupled to these linking agents by means of toluene-di-isocyanate, to give stable non-agglutinating reagents capable of coating red cells with antigen. Lipopolysaccharide from an Rd rough strain of Shigella flexneri was a particularly useful linking agent as human serum containing antibody to the smooth form of this organism did not react with the Rd lipopolysaccharide. The test is capable of detecting about 100 ng antibody/ml.