74 INTRODUCTION TO IMMUNOCHEMICAL SPECIFICITY 



When an immune serum or a "normal" isoagglutinin is found to 

 agglutinate more than one type of cell, absorption with one of these 

 types will generally remove the antibodies which affect it, leaving the 

 antibodies which react with other types of cells. The method of 

 preparation of a reagent for Ai, used before the introduction of 

 Dolichos lectin for this purpose (see Table 5-4 in Chapter 5) demon- 

 strates the behavior of "normal" isogglutinin. The serum of an in- 

 dividual of group B agglutinates erythrocytes of both subgroups Ai 

 and A^. Absorption with A2, however, removes the antibody which 

 reacts with A2 cells, leaving an anti-Ai agglutinin. Absorption of 

 an antibody to hen ovalbumin with duck ovalbumin removes the duck- 

 reactive antibody, leaving the anti-hen antibodies (some of which 

 will react also with ovalbumins of other avian species). 



If it is attempted to repeat such an experiment with a plant ag- 

 glutinin instead of an antiserum from an animal, the results are 

 generally different. Absorption with one type of cell of a lectin that 

 agglutinates two different types of cells nearly always removes both 

 types of antibodies. If, for example, we try to make the lima bean 



TABLE 6-1 



Effect of Absorption on Agglutinating Activity of 10 Per Cent Solution of Lima 

 Bean (Sieva) Proteins'' 



* Boyd and Shapleigh, 1954d. 



•^ U = undiluted. 



" After absorption, 0.05 ml. of the indicated dilution of the protein solution was 

 mixed with 0.05 ml. of a 1% suspension of erythrocytes of the indicated group 

 and the mixture centrifuged, shaken, and read microscopically. 



