Cartridges for the isolation of a biological sample and downstream biological assays on the sample are provided, as are methods for using such cartridges. In one embodiment, a nucleic acid sample is isolated from a biological sample and the nucleic acid sample is amplified, for example by the polymerase chain reaction. The cartridges provided herein can also be used for the isolation of non-nucleic acid samples, for example proteins, and to perform downstream reactions on the proteins, for example, binding assays. Instruments for carrying out the downstream biological assays and for detecting the results of the assays are also provided.