PCR Detection of Bacteria in Seven Minutes

A portable, real-time polymerase chain reaction (PCR) instrument, consisting of an array of microfabricated silicon reaction chambers with integrated optical detectors, analyzed samples of 5 to 500 bacteria cells in as little as 7 minutes. The analysis included cell lysis, PCR, detection of the PCR product with a target-specific fluorescence energy transfer probe, and automated alerting of positive signals by the software. Thermal cycle times of only 17 seconds, the fastest that could be achieved on the instrument, yielded good productivity at each cycle and indicated that still faster analysis could potentially be performed. The short run times were achieved because of efficient heating and cooling of the reactions, precision in which the target temperatures were reached, and the sensitive, dedicated mini-optical detection systems.