This invention relates generally to the field of microarray reaction devices and uses thereof. In particular, the invention provides a microarray reaction device wherein a plurality of reaction spaces are formed between a first and second plurality of projections, the heights of said plurality of reaction spaces being substantially identical and controllable by a supporting structure, and the relative positions between the first and second plurality of projections being controllable by a positioning structure. Articles of manufacture comprising the microarray reaction device and methods for assaying an analyte using the microarray reaction device are also provided.