The roboocyte: automated cDNA/mRNA injection and subsequent TEVC recording on Xenopus oocytes in 96-well microtiter plates.

Membrane-bound neurotransmitter receptors and ion channels are among the most numerous and important drug targets, and electrophysiological methods are the gold standard for the study of their functional properties and their response to drugs. However, electrophysiological measurements are usually performed one at a time by highly skilled individuals, and secondary functional screening is often hampered by this lack of throughput. Accordingly, the use of automated procedures to increase the efficiency of electrophysiological techniques is of great interest. Among the many different electrophysiological techniques that have been described, two electrode voltage clamp recording (TEVC) from Xenopus oocytes seems particularly suitable for the implementation of automated measurement systems. Here, we describe a workstation that was expressly developed for this purpose. The Roboocyte is the first (and the only currently available) instrument that automatically performs both cDNA (or mRNA) injection and subsequent TEVC recording on Xenopus oocytes plated in a standard 96-well microtiter plate. This paper describes the scientific background of the oocyte expression system for drug screening and the development of the Roboocyte. Then, some technical details of the Roboocyte system are presented and, finally, results obtained with the Roboocyte are discussed with regard to increased throughput compared with manually performed experiments. Further information can be obtained at www.roboocyte.com.