The completed master was treated with approximately 60 μl trichloro (1H,1H,2H,2H perfluoro-octyl) silane vaporized in a vacuum chamber for 1 hour. Polydimethylsiloxane (PDMS) (Sylgard 184, Dow Corning, Midland, MI) was prepared at a 10:1 ratio with its curing agent and poured onto the master, degassed and baked at 65°C overnight to cure. Holes were punched into the PDMS to provide pipettor access. The central hole was punched to approximately 10 mm in diameter. Three side access holes per side chamber were punched at 3 mm in diameter. Devices were then sonicated in acetone for 1 hour followed by sonication in isopropanol for 40 minutes. The devices were bonded to a glass coverslip (22 mm × 22 mm) using an ETP high frequency generator (Electro-technic Products, Inc., model BD-10A, Chicago, IL), creating ozone to facilitate surface oxidation. The device was then placed on a hotplate at 95°C for 30 minutes under light weight. Once bonded, the devices were re-exposed to the ozone to create an oxidized surface and placed in distilled water for storage. To prepare the devices for culture, the
