Research On The Automatic Compensation For Capacitances Transient Current In Patch-Clamp Amplifier

As an advanced electrophysiological technique, the patch-clamp has been widely applied in the research of life science. In cellular electrophysiological studies, channel ionic current is very small (picoampere to nanoampere), which needs to be preprocessed for facilitating the measurement as well as the subsequent analysis. The patch-clamp amplifier is just an extremely powerful tool for processing the small electrophysiological signals.In order to accurately record cellular electrophysiological signals, the patch clamp amplifier adopts a series of compensation technology including high-gain amplification, frequency correction, resistance and capacitance compensation and so on, wherein the capacitance compensation is one of the key technologies. In traditional patch-clamp amplifiers, the parameters for capacitance compensation are manually configured according to the observation of experimenters, which is very complicated and discommodious. The computer-controlled automatic patch-clamp amplifier, through analyzing the capacitance transient current, automatically seeks the parameters required by the compensation, which realizes the automation of capacitance compensation, simplifies the experimental process, and improves the experiment efficiency.This paper has been organized into four sections. The first one clearly elucidates the operational principle of patch-clamp amplifier and the compensatory technology, which are the fundamental for fulfilling the automation of patch clamp. The second section proceeds with the study of the circuit characteristic of whole-cell mode, and describes the study in which the circuit mode of the whole-cell patch clamp was comprehensively understood and further was changed with betterment, and the algorithm was fulfilled for the automatic compensation of the fast and slow capacitance. In the following section, the circuit mode of the patch clamp system was established with MATLAB software, and the compensatory algorithm was successfully simulated and verified, providing the theoretical basis for the achievement of automatic capacitance compensation. The last section describes the accomplished enhancements for the capacitance compensation circuit in comparison with traditional patch clamp amplifier.