Thin reaction chambers for containing and handling liquid microvolumes

Abstract

The invention is an apparatus and a process for containing and handling liquids in a thin capillary space. Two opposing walls positioned at a first and a second distance apart define a thin space having at least two different heights and two different regions of capillary liquid attraction. Enclosing the thin space with side walls defines a reaction chamber. A liquid receiving area, entry and exit ports and features projecting from, or encircling, at least one wall allow coatings on the internal surface of either of the two opposing walls to react with multiple microvolumes of reagents and wash treatments in series. Liquids flow into, or are withdrawn from, the thin space in a way in which bubbles are not introduced into the thin space. Bubbles that may arise in the thin space move along a sloped feature out of the thin space into an annular enclosure. The liquids are withdrawn after reacting with the coatings, either to empty the chamber and recover the liquid volume, or to wash the coatings with treatment liquids and introduce new treatment liquids. The ability to control liquid movement in spaces thin enough to exhibit capillarity is useful for analyzing biological specimens cost-effectively with less reagent volume and more information per specimen and without sacrificing convenience in liquid handling or surface reaction space.