A porous polystyrene (PS) film with a well-ordered pore structure (see figure) prepared by using the breath-figure method is used as a template to pattern proteins. Amino-terminated PS is used to produce an amino-terminated surface on the pores in the film and fluorescein-isothiocyanate-conjugated bovine serum albumin is attached to the surface through crosslinking of glutaraldehyde. This is a nonlithographic method for 3D protein micropatterning.