A simplified method for screening acetylcholinesterase inhibitors by the flesh fly (Dipt., Sarcophagidae) cell culture system

A simplified economical method for assaying acetylcholinesterase inhibitors was devised. A flesh fly, Sarcophaga peregrina Robineau-Desvoidy, cell lin e, NIH-SaPe-4, was cultured in 96-well microplates at 25 degrees C. After 2 days culture, the culture media was removed and phosphate buffer was intro duced. The cells were disintegrated by freezing-thawing, and a reaction mix ture containing substrate, inhibitor, and colour developer was added. The c hange of absorbance at 405 nm at 25 degrees C was measured with a microplat e photometer and the concentration of the test substance required to inhibi t the enzyme reaction by 50% (I-50) was calculated.