MEASURING THE VISCOELASTIC PROPERTIES OF HUMAN PLATELETS WITH THE ATOMIC-FORCE MICROSCOPE

We have measured force curves as a function of the lateral position on top of human platelets with the atomic force microscope. These force curves show the indentation of the cell as the tip loads the sample. B y analyzing these force curves we were able to determine the elastic m odulus of the platelet with a lateral resolution of similar to 100 nm. The elastic moduli were in a range of 1-50 kPa measured in the freque ncy range of 1-50 Hz. Loading forces could be controlled with a resolu tion of 80 pN and indentations of the platelet could be determined wit h a resolution of 20 nm.