SAMs at the micrometer scalel pCP uses an elasto- meric stamp having at its surface a pattern in relief to transfer an alkanethiol to a surface of gold or sil-

This paper describes a convenient methodology for patterning substrates for cell culture that allows the posi t ions and dimensions of at tached cel ls to be controlled. The method uses self-assembled monolayers (SAMs) of terminally substituted alkanethiolates (R(CHr)r , , rS-) adsorbed on opt ical ly t ransparent fi lms of gold or silver to control the properties of the substrates. SAMs terminated in methyl groups adsorb protein and SAMs terminated in oligo(ethylene glycol) groups resist entirely the adsorption of protein. This methodology uses microcontact pr inting (pCP) an experimentally simple, nonphotol i thographic process-to pattern the format ion of SAMs at the micrometer scalel pCP uses an elastomeric stamp having at its surface a pattern in relief to transfer an alkanethiol to a surface of gold or silver in the same pattern. Patterned SAMs having hydrophobic, methylterminated l ines 10, 30,60, and 90 pm in width and separated by protein-resistant regions l2O p"m in width were prepared and coated with fibronectin; the protein adsorbed only to the methyl-terminated regions. Bovine capil lary endothelial cells attached only to the fibronectin-coated, methyl-terminated regions of the patterned SAMs. The cells remained attached to the SAMs and confined to the pattern of underlying SAMs for at least 5 7 days. Because the substrates are optically transparent, cells could be visualized by inverted microscopy and by fluorescence microscopy after f ixing and staining with fluorescein-labeled phalloidin. o rseT