Long-term Monitoring of Bacteria Undergoing Programmed Population Control in a Microchemostat

Materials and Methods Microfluidic device design and fabrication: The microchemostat chip was fabricated out of the silicone elastomer polydimethylsiloxane (PDMS) (General Electric RTV 615) using multi-layer soft lithography, as described previously (S1). Six reactors run in parallel on each chip. The microchemostat reader: The reader consists of a Nikon TE 2000 (A. G. Heinze Inc., Lake Forest, CA) inverted microscope furnished with a PRIOR Scientific XYZ motorized stage system (A. G. Heinze Inc., Lake Forest, CA). Imaging was done using a Plan Fluor 40X 0.75NA ph2 DLL objective. The images were captured by a chargecoupled device (CCD) camera and digitized by a PXC200 color frame grabber (Cyberoptics Semiconductor, Beaverton, OR). We developed Labview software to control the synchronized operation of these components and all chip operation.