Hapten immobilization for antibody sensing using a dynamic modification protocol

Optical fiber (OF) sensors are often limited by the immobilization technique used to associate a specific sensing ligand with the OF surface. This is particularly true when the ligand is biologically active as, for example, in the case of immobilized haptens or antibodies. The dynamic modification protocol is a regenerable and experimentally simple way to immobilize a variety of sensing molecules on an OF surface. Furthermore, the protocol is immune to hydrolysis and not limited by diffusion through a membrane or sol–gel. In this publication the approach is extended by immobilizing the hydrophobic hapten (octadecyl 6-(2,4 dinitrophenyl)aminohexanoic acid) as a means to prepare an OF sensor for antibodies specific for 2,4 dinitrophenyl (DNP). The LOD for anti-DNP is 0.5 nanomolar and the K_apparent is 1.0±0.2×10⁶. Nonspecific antibody adsorption is problematic in this sensing approach and was found to limit the quantitative capabilities of the sensor. However, time discrimination can be used to allow the nonspecific antibody to desorb prior to measurement thus minimizing the influence of nonspecific binding on sensor performance.     

Development and characterization of new polyclonal antibodies specific for three polychlorinated biphenyls

Three polychlorinated biphenyls(PCBs)congeners and their corresponding haptens bearing four carbon length carboxylic groups that can be linked to a protein for raising antibodies were synthesized.The three resultant immunogens were fabricated and used to stimulate immune responses in rabbits to survey the characteristics of the haptens.Three of the resultant polyclonal antibodies(Pabs)were obtained.The antiserum exhibited relatively high antibody titres(1:32-64)in double agar diffusion.◎2008 Hui Sheng Zhuang.Published by Elsevier B.V.on behalf of Chinese Chemical Society.All rights reserved.     

Flow-injection enzyme immunoassay of haptens with enhanced chemiluminescence detection

A non-equilibrium flow-injection enzyme immunoassay for thyroxine (model hapten) involving affinity separation of the immunocomplex of horseradish peroxidase-labelled antibodies and antigen from the free labelled antibodies is described. An enhanced chemiluminescence reaction was used for detection of horseradish peroxidase as an antibody marker. The method allows the determination of thyroxine concentrations as low as 10^?11 M within 5 min and the precision is 10% (relative standard deviation).