An integrated cartridge for sample processing and analysis is disclosed. The integrated cartridge contains a sample preparation chamber having a sample inlet and a sample outlet, and a sample purification chamber adapted to receive a replaceable sample purification unit containing a housing and an extraction filter inside the housing. The extraction filter specifically binds to a molecule of interest. The sample purification chamber has a sample inlet that is in fluid communication with the sample outlet of the sample preparation chamber. Also disclosed is a microarray-based sample analysis (MBSA) system.