MOLECULAR COMPLEMENTARIIStESS'INANTIGEN-ANTIBODY SYSTEMS 



Fig. lb 



gen would have a long invagination to accommodate the hapten. The lit would 

 be all around the hapten but perhaps not very close in view of the length of 

 the mvagmation, ca. 12 A. In the second case, the antibody would be formed 

 against the face of the hapten group, and in the third, the antibody would have 

 a slit trench type of anti-hapten region with one side open to accommodate 

 the hapten. Evidence is available that indicates that these three types of anti- 

 body do exist. 



Another point to bear in mind is that the antibody is Cjuite heterogeneous. 

 An antiserum formed against even a simple hapten contains a mosaic of differ- 

 ent antibody molecules, each having specificity directed toward particular 

 portions of the hapten. Thus Landsteiner and van der Scheer prepared anti- 

 serum against a hapten containing two different groupings, 5-azoisophthalyl- 



