Category: Automation and High-Throughput Technologies
Enzyme-linked immunosorbent assay (ELISA) is a traditional analytic method in which nonspecific and unbound components are washed away after each reaction process. In case performing high-throughput screening (HTS) for drug discovery using ELISA, it can be expected to reduce false positives and negatives interfering with assay signal because test compounds are eliminated in plate wells before signal readout. However, ELISA requires many steps to add and remove reagents, therefore, miniaturization and automation of the assay is challenging.
We tried to develop an ELISA with 1536-well format for performing HTS to discover enzyme inhibitors. As immobilization of a substrate was critical for obtaining a biological activity for our target enzyme, both enzymatic reaction and product detection were carried out in single well. The kinetics of the enzyme activity was able to be analyzed with our developed ELISA. Although the ELISA required over 15 steps of reagent addition, washing plate or compound transferring, Z’-factor constantly showed to be over 0.8 through multiple plate run with the integrated robot system. Besides preventing evaporation of plate contents, removing air bubbles in dispensed reagents and reducing residual liquid after washing steps by centrifugation were effective for maintaining assay quality. By using the ELISA, our full compound library was successfully screened.
Koji Enomoto– Associate Principal Scientist, SHIONOGI & CO., LTD., Toyonaka, Osaka, Japan