Abstract: A device for carrying out a reaction, which device comprises a wafer provided with a group of at least two wells. The wells are thermally separate from each other by means of a groove in a layer of the device, while parts separated by the groove are locally connected by bridges. In this way a device is provided combining great mechanical strength with good thermal insulation.

Abstract: The invention relates to a method of performing a fluorescence assay. According to the invention a filter is integrated with at least one component chosen from i) a body comprising a well, wherein the well in which the assay is being performed is exposed to excitation light in such a manner that the filter is positioned between the light-sensitive element and the excitation light source, and ii) a light-sensitive element, wherein the filter is applied at least at the light-sensitive side of the surface of the light-sensitive element, and any light that may be emitted is detected by means of the light-sensitive element. The invention also relates to an apparatus suitable for carrying out the method, as well as a method for its manufacture.