Combining force and fluorescence microscopy for the manipulation and detection of single cells, viruses, and proteins

Abstract

AFM imaging revealed a decoration of the actin laments with the 'cross-linking' DBN-1 proteins.As an additional project an 'optical AFM' was developed. This instrument is based on optical tweezers and specically designed to overcome the noise limitations of AFM at low forces. The trapped bead is moved in the direction perpendicular to the microscope cover slide so that cells can be indented in a similar fashion as with AFM. It was constructed to perform force spectroscopy experiments on cells at very low forces.i Since for micrometer sized objects the Reynolds number is very low (∼ 10 −4 ), inertial forces are neglected.