Summary
Complement-independent precipitin lines in double diffusion analysis of anti-hapten sera and hapten protein conjugates may show spurs within a single haptenic system. This phenomenon is observed when anti-DNP antibodies are analyzed with DNP conjugates with different numbers of haptenic groups. A spur is observed when the line formed by the highly conjugated antigen joins the line of the lesser conjugated antigen. This phenomenon is explained by the formation of soluble antigen-antibody complexes between antibody and DNP-BSA of relatively low degree of conjugation which are precipitated by DNP-BSA of high degree of conjugation. A similar finding is observed with the cross-reacting haptenic system—pentaCIB-DNP. An anti-pentaCIB serum causes the formation of a precipitin line with highly conjugated DNP-BSA which spurs over that formed with pentaCIB-BSA conjugated to a lesser degree. In anti-hapten systems spur formation of complement independent precipitin lines is not entirely predictable upon the basis of antigenic relationship.
Footnotes
Supported by Public Health Service Grant AI04983 and the Health Research Council of the City of New York, Contract I-138.