In one embodiment of the invention, there is provided a method of selecting a surface chemistry for culturing a given cell line, including the steps of: (i) providing a first substrate having a plasma polymerized surface with first and second regions, said first region having a first concentration of carboxylic acid groups on said plasma polymerized surface and said second region having a second concentration of carboxylic acid groups on said plasma polymerized surface, wherein said first and second concentrations are different; (ii) culturing cells from said cell line on said plasma polymerized surface in each said region; (iii) observing activity of said cultured cells in each said region, said activity selected from the group consisting of alkaline phosphatase activity of the cultured cells, cell growth of the cultured cells, attachment of the cultured cells, and cell spreading of the cultured cells; and iv) selecting, based on a particular observed activity, a secondary substrate for culturing said cells wherein the secondary substrate has a plasma polymerized surface having a constant concentration of carboxylic acid groups thereon which is equal to the concentration of carboxylic acid groups in the region on said first substrate wherein the cells exhibit said particular observed activity.