Development of enzyme-linked immunosorbent assays for the organophosphorus insecticide EPN.
Competitive enzyme-linked immunosorbent assays (ELISAs) in indirect and direct format were developed for the quantitative detection of the organophosphorus insecticide EPN. Five EPN derivatives (haptens) were synthesized and coupled to carrier proteins to use as an immunogen or as a competitor. Rabbits were immunized with two of the five haptens coupled to KLH for production of polyclonal antibodies, and the sera were screened against one of the haptens coupled to ovalbumin (OVA). Using the serum with the highest specificity and a coating antigen (hapten-OVA conjugate), an indirect (antigen-coated) ELISA was developed, which showed an IC(50) of 5.6 ng/mL with a detection limit of 0.2 ng/mL (20% inhibition). A direct (antibody-coated) ELISA using an enzyme tracer (hapten-enzyme conjugate) was also developed, which showed an IC(50) of 8.4 ng/mL with a detection limit of 0.9 ng/mL (20% inhibition). The antibodies showed negligible cross-reactivity with other organophosphorus pesticides except with the insecticide parathion-ethyl only in the direct ELISA. The recoveries of EPN from spiked samples determined by the indirect ELISAs were between 37 and 164%.
Shim
Jee Youn
JY
Department of Food Science and Nutrition, Kyungpook National University, Daegu 702-701, Korea.
Kim
Young Ah
YA
Lee
Eun Hye
EH
Lee
Yong Tae
YT
Lee
Hye-Sung
HS
D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006241:Haptens / Q000032:analysis / Q000737:chemistry / Q000276:immunology; D007114:Immunization; D007306:Insecticides / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D011817:Rabbits
D006241:Haptens; D007306:Insecticides; D009943:Organophosphorus Compounds