Adaptive Platform for Highly Parallel Low-Noise Recordings of Single Membrane Proteins

Abstract

Highly parallel, low noise electrophysiological recordings of single ion channels are of interest both for basic research and drug development. Here, a microsystems approach is presented (see Fig.1A) which greatly simplifies the recording configuration and optimizes the electrical parameters governing noise. The lipid bilayer is formed on a picoliter cavity generated within a photochemical resist acting as a dielectric (see Fig. 1B). On the bottom of each cavity a microelectrode is placed.Fig. 1Patch16Chip (B)Connecting lines and cavities over the circular shaped electrodes. (C)Current traces of single alamethicin-channels, detected in parallel at 9 different cavities.View Large Image | View Hi-Res Image | Download PowerPoint SlideUsing standard photolithographical techniques this design allows for many such setups on one chip, and is therefore in principle well suited for highly parallel single channel recordings. Parallel recordings (16-electrode multiarray) of currents mediated by alamethicin are shown (see Fig.1C), illustrating the potential of this novel approach towards high-throughput measurements of single membrane proteins. Furthermore, the flexibility of this approach is outlined by the reconstitution of α-hemolysin in the lipid bilayer. The capability for molecular analysis is demonstrated by the detection of oligomers diffusing through the bacterial pores.