| 摘要 |
The present invention disposes a membrane, for example, a biological cell membrane including amphiphilic lipids, cholesterol and proteins, between two electrical conductive walls having a height at least as great as the thickness of the membrane. The conductive walls are fabricated on an electrically insulative chip base. Electrical conductors extend from each of the conductive walls on the base. An electric field is propagated between the conductive walls in the plane of the membrane. The chip base has one or more through hole between the electrically conducting walls where the membrane is deposed. The chip is placed inside a container that has a base and can have a surrounding wall. The container base has a well below the through hole of the electrically insulative base when it is placed inside the container. At least one passageway extends from the well to the periphery of the container. A third electrode can be fabricated on the bottom of the well. This invention probes changes of the membrane as an in-plane electric field is applied between the conductive walls, using electric current measurements, impedance gain phase analysis, raster scanning by atomic force microscope, and observation with confocal, fluorescence or other microscopes, but not limited to these tools. The invention probes cellular processes such as structural changes of proteins, channeling mechanisms, protein-protein interactions and interaction of proteins with other molecules in an environment that mimics that of an actual living cell membrane. The well, i.e., the interior of the cell, may include various ions, proteins, RNA, DNA, and various cellular components in a suitable medium while extracellular materials such as ions, ligands and other molecules in a suitable medium can be placed in contact with the top of the membrane. Movement of the electrically charged particles through the membrane can be monitored by probing the voltage change across the third electrode and another electrode, for example the AFM tip, placed in contact with the membrane in the exterior fluid. The passageways are used to introduce substances into and out of the well. |
