Fibronectin

Micro-contact printing was used to stamp islands of fibronectin onto polydimethylsiloxane (PDMS; Dow Corning) coated glass slides. Master silicon wafers were patterned by standard photolithography techniques and used to cast PDMS template stamps43 44 (link). Featureless PDMS stamps were coated with 25 μg/ml human fibronectin (BD Biosciences) for 2 h, rinsed thoroughly with 1× phosphate buffered saline (PBS) and were dried with a stream of nitrogen. The template stamps were UV-oxidized for 7 minutes and brought in conformal contact with the featureless stamps to remove fibronectin. The stamps were then brought into conformal contact with PDMS-coated glass coverslips to transfer fibronectin islands of defined shape and size to the coverslip surface. Coverslips were then incubated with a solution of 1% Pluronics F127 (Sigma) to passivate regions not stamped with protein in order to prevent cells from adhering to these regions of the coverslip surface. Following rinsing with 1× PBS, cells were plated in cell culture media to the micropatterned coverslips. After 30 min, samples were rinsed to remove non-adherent cells.