A method and system for selectively processing a sample according to one of a plurality of different assays, for example, for detecting a certain target component in the sample, include a plurality of cartridges in which the processing of a sample can take place and which each contain a different set of reagents required for one of the assays. Moreover, the system further includes a manipulator for introducing a sample into a selected one of the cartridges. Depending on the assay to be performed with a sample at hand, the appropriate cartridge is chosen, and the sample is introduced into and processed in the cartridge.