Imaging of focal contacts of chicken heart muscle cells by high-frequency acoustic microscopy

A study of the adhesion of embryonic chicken heart muscle cells was conducted with a newly developed time-resolved acoustic microscope, which operates in the GHz-frequency range. The interpretation of the acoustical images of the heart muscle cells was done in combination with the fluorescence optical microscopy. A comparison between the acoustical images of chicken heart muscle cells and optical images of the same cells after staining showed that the actin fibers end inside the dark streaks in the acoustical images and thus represent the focal contacts (FCs). For cell biology applications, this demonstrates (a) the use of SAM as a tool for studying the dynamics of the FCs of living cells without any chemical staining and (b) that the combination of acoustic and optical microscopes allows interpretation of the acoustical images by using the wide variety of techniques available in optical microscopy.