Figure 1.

Detail of the microfluidic device for on-chip staining and counting Long and short lengths are 50 mm and 25 mm, respectively. Width of the channel is 100 μm, with the exception of the “mixing part” (500 μm). Depth of the channel is 15 μm. Sample, fluorescent dye solution and sheath fluid were injected at each inlet. The process of on-chip staining and counting of bacterial cells is shown and includes: (i) the sample and fluorescent dye solution flowing separately and becoming mixed in the “mixing part” of the microchannel, (ii) alignment of the sample flow by the sheath fluid, and (iii) the flow of bacterial cells in the “detecting part” of the microchannel.