A novel lab-on-a-chip has been developed to identify pneumonia-causing bacteria from bronchoalveolar lavage samples within hours, instead of days.

Inside the chip, the bacteria flow into several different compartments -- eight in the current version of the chip -- and are made to stick to a bacteria-friendly surface using an electric current. Antibodies then flow in. The antibodies bind specifically to certain strains of bacteria, and mark them with fluorescent dyes of different colors. The dyes color-code cells from known strains. A Microscope monitors the viable cells -- those that are still reproducing -- and the rate at which they duplicate helps to identify their species.
In the next step, different antibiotics are pumped into the chambers. If the cells in a chamber stop reproducing, that indicates that a certain drug is likely to be effective at fighting the infection. The death of the bugs is confirmed by checking with a special dye

The developers, Accelr8, says the technology may also be applies in testing the efficacy of new drugs on unknown strains. A paper entitled "Microfluidic Devices That Capture Bacteria for Growth and Kill Analysis" has been presented during the recently concluded 53rd AVS International Symposium & Exhibition, at San Francisco, CA.