NIH3T3 cells transfected with the GFP-TN-C promoter based reporter construct were plated onto the different surface preparations at the same density, and after 24 hours they were fixed, stained with DAPI and Texas Red-C2-maleimide. For each surface, all the cells in 50 fields were analyzed using automated microscopy (with several hundreds of cells sampled per surface). Fibronectin thin film, ●; thin film of fibrillar collagen (▲), thin film prepared from a lower concentration of collagen (◆). Error bars reflect the standard deviation of a minimum of four samples derived from at least two replicate experiments. While these data are the results from transfected fibroblasts, untransfected NIH3T3 cells exhibit equivalent areas and distributions of areas in response to these different matrices.