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. By analyzing these force curves we were able to determine the elastic modulus of the platelet with a lateral resolution of approximately 100 nm. The elastic moduli were in a range of 1-50 kPa measured in the frequency range of 1-50 Hz. Loading forces could be controlled with a resolution of 80 pN and indentations of the platelet could be determined with a resolution of 20 nm.
Radmacher
M
M
Department of Physics, University of California, Santa Barbara 93106, USA. manfred@physics.ucsb.edu
Fritz
M
M
Kacher
C M
CM
Cleveland
J P
JP
Hansma
P K
PK
D055592:Biophysical Phenomena; D001703:Biophysics; D001792:Blood Platelets / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure*; D048429:Cell Size / Q000502:physiology; D003599:Cytoskeleton / Q000737:chemistry / Q000502:physiology; D004548:Elasticity; D006801:Humans; D066298:In Vitro Techniques; D018625:Microscopy, Atomic Force / Q000379:methods*; D008954:Models, Biological; D015539:Platelet Activation / Q000502:physiology; D014783:Viscosity