Studies on the Effect of the Carrier Molecule on Antihapten Antibody Synthesis

1. Fluorescence quenching has been calibrated, by comparison with equilibrium dialysis, for measurement of antibody-hapten association constants with guinea pig antibody to the 2,4-dinitrophenyl (DNP) determinant. The maximum quenching with all sites occupied which gave best agreement with equilibrium dialysis was found to be 100%. 2. The carrier to which the DNP-hapten is coupled influences significantly the amount, class (gamma(1) or gamma(2)), and affinity of the antibody of DNP specificity made by individual guinea pigs. 3. The affinities of gamma(1)- and gamma(2)-antibodies from individual guinea pigs are generally very similar. 4. Precipitin curves with gamma(1)-antibodies show more marked inhibition of precipitation in antigen excess than do precipitin curves with the less charged gamma(2)-antibodies, indicating the importance of nonspecific forces in the precipitation reactions.