Production and characterisation of polyclonal antibodies to the common moiety of some organophosphorus pesticides and development of a generic type ELISA

Most of the commonly used organophosphorus (OP) pesticides share a similar moiety in chemical structures. We used this moiety [(CH3O)(2)-P(S)-O-] to s ynthesise a 'generic-OP' hapten, which was linked through a 4-carbon spacer to bovine serum albumin (BSA), against which polyclonal antibodies (PAb) w ere raised. Other analogues of the generic-OP hapten were also prepared wit h varying lengths of spacer group and used in an inhibition ELISA, develope d for PAb characterisation. Greater inhibitions of the PAb were recorded wi th Fenitrothion, Methacrifos, Propetamphos and Dichlorvos with 50% inhibiti on values of 4.8, 8.2, 36.2 and 91.1 mu g ml(-1) respectively. Compared to these OPs, in which phosphorus is linked to specific side groups via an oxy -ester link, other compounds either with a thio-ester link or in which side group contains a pyridine or pyrimidine ring, showed much lower inhibition . Using analogues of the generic-OP hapten as inhibitors, the greatest inhi bitions of the PAb were recorded with hapten containing a 4-carbon spacer g roup, and progressively lower inhibitions with a decrease in length of spac er. However, some inhibition of the PAb was noted for the generic-OP analog ue with a single carbon side group. The information gained from these studi es will be useful in the design of immunogens for other small molecule hapt ens, and production and use of generic PAb against a group of chemically-si milar compounds.