A novel experimental chamber for single-cell voltage-clamp and patch-clamp applications with low electrical noise and excellent temperature and flow control.

We describe a simple and inexpensive experimental chamber that is designed to overcome several problems encountered when doing electrical and optical studies on single cells or on isolated membrane patches. The bath is small enough to fit on the stage of a standard inverted microscope. It includes a novel solution level-detector, the output of which is used to actively control the level of solution in the experimental chamber. A Peltier-effect device is located adjacent to the flow-chamber and heats or cools the inflowing solution. Solutions can be rapidly switched using two electrically actuated microvalves. The attraction of this system is that, with appropriately quiet power supplies, not only is the bath solution-level held at a fixed height, but the temperature of the bathing solution can also be set over a wide temperature range (minimum range is 15 to 45 degrees C), and solutions can be rapidly changed. All of the construction details are supplied as are appropriate electrical circuits. Without modification, the chamber can be used for applications as diverse as fluorescence microscopy of living cells, time-lapse photomicroscopy and single-cell motion detection as well as single cell voltage-clamp and isolated membrane patch-clamp. With simple modification the system can be adapted for use in experiments on multicellular preparations.