Effect of Carrier Surface Modification on the Resultant Antibody to Folic Acid

For the generation of antibodies against small hapten molecules, the hapten is cross-linked with some carrier protein to make it immunogenic. However, it was rarely systematically studied about the effect of modified carrier protein on the obtained antibody nature. In this study, folic acid as the model hapten was coupled to natural and surface-modified bovine serum albumin (BSA) using modifying agent amidocaproic acid (ACA) and hexamethylene diamine (HDA). The three immunogens of FA-BSA, FA-ACA-BSA, FA-HDA-BSA were confirmed by SDS-PAGE and ultraviolet spectrum (UV). The Balb/C mice were immunized with the artificial antigen to obtain three specific antibody with indirect competitive enzyme-linked immunosorbent assay (icELISA) method to compare the performance of antibodies obtained based on different imunogen. The results indicate that the conjugates were successfully synthesized and the coupling ratio from the high to the low was HDA-BSA > ACA-BSA > BSA, while the titer of antibody was ACA-BSA > BSA >HDA-BSA and the IC50was HDA-BSA < ACA-BSA < BSA. This suggests that sensitivity of antibody was improved by cationizing the carrier protein.