Supplementary Information: Fast size-determination of intact bacterial plasmids using nanofluidic channels

Materials and Methods Nanofluidic chips Nanofluidic chips were fabricated from a silicon wafer with 2 μm thermal oxide in cleanroom facilities at Chalmers University of Technology. Nanochannels were created by electron-beam lithography (JBX-9300FS/JEOL Ltd) and reactive ion etching (Plasmalab 100 ICP180/Oxford Plasma Technology). Microchannels were made by optical lithography (MA 6/Suss MicroTec) and subsequent reactive-ion etching. Inlets were created by optical lithography and deep reactive-ion etching (STS ICP/STS). The wafer was sealed with a 175 μm thick Pyrex lid through fusion bonding (AWF 12/65/Lenton) and diced into 25x25 mm2 chips (DAD3350/Disco). The methods are further described in reference [1].