(a) An integrated device that automatically performs a multistep HIV genotyping assay. At the beginning of the process reagent mixtures are loaded into storage chambers S1–S6. The device automatically carries out RNA purification from a serum lysate (extraction), RT–PCR, nested PCR, DNase fragmentation and dephosphorylation, terminal transferase labeling, dilution and hybridization, washing, phycoerythrin staining and washing (in chambers R1, R2, R3, R4, R5 and R6, respectively). Intermediate product samples are stored in chambers M1–M4 for later analysis. Three independently controlled temperature zones are indicated as Storage Zone, Reaction Zone and Hybridization Zone on this polycarbonate device with dimensions of 8 × 40 × 70 mm. (b) Process flow schematic of the automated HIV assay. The introduction of bulk reagents (washes and buffers) from externally connected vials is controlled using cartridge-based valves. Frag refers to the DNase fragmentation and dephosphorylation reaction, Phyco Stain to the streptavidin–phycoerythrin conjugate and Buff1, Buff2, and Buff3 to buffers for hybridization, washing and staining, respectively.