Glass capillary microfluidic device

Glass capillary microfluidic device was fabricated by assembling tapered round capillary, square capillary and syringe needles together using 5 minutes epoxy (Fig. S1)⁴⁹. First, the round glass capillary (Sutter Instrument B100-58-10) was pulled using a pipette puller (Sutter Instruments P-87). The tapered capillary was then sanded using 1200 grade sandpaper to obtain a 100 μm opening for the collection tube. The outside surface of a clean 15 μm opening injection tube, pulled and similarly sanded, was treated with trichloro(1H,1H,2H,2H-perfluorooctyl)silane to render the surface hydrophobic. Then, the injection tube and collection tube were inserted into a square capillary (AIT, 810-9917) placed on a glass slide and they were aligned under an optical microscope. Syringe needles (McMaster Carr, 75165A677) were cut and glued to the glass slide using 5 minutes epoxy (Devcon, 14250). Lastly, micro-tubings (Scientific Commodities, BB31695-PE/5) were connected to the syringe needles.