[Production and characterization of antisera against O,O-diethyl-O-(p-nitrophenyl)-phosphate (paraoxon)]

Methods for the production of antibodies against Paraoxon in rabbits are described. The highest-titre antisera were produced with conjugates containing a succinyl spacer group with a degree of derivatisation between 8 and 12 haptens per albumin molecule. The antibody response was tested by immunoprecipitation in agar gel with a hapten-rabbit-albumin-complex and by a radioimmunoassay. The synthesis of 125I labelled tracers is reported. The most potent antisera bound 50% of the radioactive tracer after 1:10(5) dilution and showed apparent affinity constants of 10(6) to 10(7) M-1 for Paraoxon. Compared to Paraoxon these antisera possessed cross reactivities with Parathion of 8.8 to 13.8%, with Methylparathion of 0.35 to 0.82%, and with Dimethoat of 0.0006 to 0.0012%.