Precipitin reaction between antigenic

These reactions differ from the pseudoimmune reactions reported by Edwards and Jones (30). because the cotton dust anti gen(s) does not react nonspecifically with both normal and immunized rabbit sera. Precipitin arcs in a reaction of identity between antigens in bracts and dust in Figure 2 confirm that antigens present in dust are derived at least partly from cotton bract. 

It was noted in previous reviews (1,3) that injection of urease into rabbits elicited an antibody and that the precipitate formed between urease and its antibody still possessed catalytic activity. This indicates that the antigenic and catalytic regions are not identical. A more recent study employing horse and rat antisera (66) revealed only one major antigenic component in urease preparations and confirmed the lack of complete enzyme inhibition by the precipitin reaction. 

Diffusion in agar performed by the conventional method shows a strong reaction between the antibody and Man-BSA, but not with BSA (Fig. 12, plates A). However, both compounds give precipitin complex with anti-BSA serum. Oxidation of the antigens with periodate no longer gives a precipitin reaction with the anti-mannose antibodies, but has no effect on the anti-BSA antibodies. Hapten-inhibition results are also shown in Fig. 12, plates C and D. These tests are conducted with the purified antibody... 

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