An optimized microtiterplate assay to detect acetylcholinesterase activity in individual <i>Chironomus riparius</i> Meigen

Abstract

Abstract A sensitive microtiter plate assay to detect acetylcholinesterase activity in fourth-instar Chironomus riparius (Meigen) larvae was developed and optimized to allow the measurement of pesticide inhibition in individuals. Optimal conditions, including enzyme concentration, pH, and substrate concentration, allow the sensitive measurement of changes in activity following exposure to the organophosphate insecticide chlorpyrifos. Significant reductions in activity were observed at pesticide doses of 0.05, 0.1, 1.0, and 5 mg/L following a 48-h exposure.