Figure 4

Comparison of phase contrast, fluorescence and SPR imaging of fixed vSMC 24 h after plating on 300 μm squares of fibronectin separated by 50 μm lines of PEG-thiol. A) Phase contrast (left frame) and Texas Red fluorescence staining (middle frame) images acquired with a 10×/0.3 N.A. objective on an inverted optical microscope; the SPR image (right frame) was collected on the instrumental set up described herein using 470 nm incident light. The color scale bar indicates reflectivity values. The SPR image displays distinct intensity differences between PEG-thiol regions (dark blue), areas of fibronectin (light blue) and cell-substrate contacts (green to red). The spatial scale bar indicating 100 μm applies to all images. B) Comparison of contrast using the three methods of imaging features under the white lines in (A). C) Selected regions of the fluorescence (left) and SPR (right) images with cell edge contours overlaid from opposing image. Scale bars = 100 μm.