AFM image overlaid with the epifluorescence image of a patterned cardiac myocyte.

A rat cardiac myocyte was cultured on a micro-contact-printed square island of extra-cellular matrix (ECM) protein. The cell was fixed and stained for actin (green), sarcomeric alpha-actinin (red) and DNA (blue). After fixation, the cell was scanned by AFM. Merged topography and fluorescent images reveal that the actin/alpha-actinin myofibrils and the nucleus are responsible for specific AFM topography. The 92 µm image was taken by the Disease Biophysics Group at the School of Engineering and Applied Sciences, Harvard University, headed by Prof. Kevin Kit Parker. Image courtesy of K. Parker and N. Geisse, Harvard University.