Method for detection of at least one target molecule and/or product molecule, comprising the following steps: a) making available a base surface with open cavities and a covering device, wherein (i) reaction components are present on the base surface and/or the covering device, in defined regions, wherein the defined regions lie on the base surface within the area of the cavities and there are at least two defined regions with different reaction components, and (ii) the base surface has a liquid barrier that forms an edge around the cavities of the base surface, and a region for making the reaction solution available, and (iii) the covering device comprises spots and a spot of the covering device covers multiple cavities of the base surface, b) adding the reaction solution to the region for making the reaction solution available, wherein the reaction solution contains the target molecules, c) placing the covering device on the base surface, so that the covering device is arranged within the liquid barrier, wherein the reaction solution is distributed among the cavities by means of placing the covering device on, the reaction solution penetrates into the cavities, and each cavity, together with the covering device, forms a closed reaction space after placing on the covering device, d) carrying out an amplification reaction, a detection reaction and/or a derivatization reaction, wherein the reaction solution comes into contact with the reaction components and product molecules are formed, and e) detecting at least one target molecule and/or product molecule, wherein at least two different sections of the target molecule and/or product molecule are detected in separate, closed reaction spaces and/or at least two different target molecules and/or product molecules are detected in separate, closed reactions spaces. a) making available a base surface with open cavities and a covering device, wherein (i) reaction components are present on the base surface and/or the covering device, in defined regions, wherein the defined regions lie on the base surface within the area of the cavities and there are at least two defined regions with different reaction components, and (ii) the base surface has a liquid barrier that forms an edge around the cavities of the base surface, and a region for making the reaction solution available, and (iii) the covering device comprises spots and a spot of the covering device covers multiple cavities of the base surface, (i) reaction components are present on the base surface and/or the covering device, in defined regions, wherein the defined regions lie on the base surface within the area of the cavities and there are at least two defined regions with different reaction components, and (ii) the base surface has a liquid barrier that forms an edge around the cavities of the base surface, and a region for making the reaction solution available, and (iii) the covering device comprises spots and a spot of the covering device covers multiple cavities of the base surface, b) adding the reaction solution to the region for making the reaction solution available, wherein the reaction solution contains the target molecules, c) placing the covering device on the base surface, so that the covering device is arranged within the liquid barrier, wherein the reaction solution is distributed among the cavities by means of placing the covering device on, the reaction solution penetrates into the cavities, and each cavity, together with the covering device, forms a closed reaction space after placing on the covering device, d) carrying out an amplification reaction, a detection reaction and/or a derivatization reaction, wherein the reaction solution comes into contact with the reaction components and product molecules are formed, and e) detecting at least one target molecule and/or product molecule, wherein at least two different sections of the target molecule and/or product molecule are detected in separate, closed reaction spaces and/or at least two different target molecules and/or product molecules are detected in separate, closed reactions spaces.