Glass bottom cell culture dish

A patterned master of photoresist (SU-8, Microchem) was created via UV light through a laser printed mask. Polydimethysiloxane (PDMS, Polysciences, Inc) was then polymerized on top of the master to create a stamp with 9 μm spaced grids, such that FITC conjugated and non-FITC conjugated adhesion proteins were placed in alternating 9 μm intervals along both the X and Y axes. In principle, there is no limitation on grid periodicity provided that it can be resolved by the imaging system. A mixture of 25μg/ml of fibronectin and 25 μg/ml of FITC conjugated fibrinogen was incubated with Sodium Periodate (Sigma Aldrich) for 20 min to yield free aldehydes. This incubation took place on top of the patterned PDMS stamp for 30 mins, air dried and then applied to the surface of the hydrogel, which had been dried in room temperature for 40 minutes (Fig. 1B). Next, 25 μg/ml fibronectin on a blank PDMS stamp was applied onto the hydrogel, following the same procedures as the previous step (Fig. 1C). By following these procedures, we obtained a uniform distribution of adhesion proteins on the gel surface for attachment of cell with periodic regions displaying fluorescence signal. The coverslip with the gel was then glued to the bottom of a glass-bottom cell culture dish (MatTek) at two points using tissue adhesion glue (Liquid bandage, CVS).