A robotic inkjetlike nozzle places viral RNA on a microarray to populate it with more than 100 variations bits and pieces of RNA called markers, that together identify the exact strain of the virus. Body fluids from the patient are amplified with a polymerase chain reaction, which makes thousands of copies for testing many simultaneous possibilities within the same microarray, and these are applied over the entire array. After that, the array is "developed" thermally and irradiated with a laser to induce fluorescence.
Any matches will show up as glowing dots in a known location on the microarray, thus identifying the matching DNA sequence. Using a variety of known sequences, new viral DNA can usually be identified and sequenced in a few weeks to a month. SARS, for instance, was identified in this way in a coordinated worldwide effort of just a few weeks.
After the virus is identified, microarrays can be stamped out like the microchips they are, and sent around the world for insertion into diagnostic gear, or readers.