Microrheology of entangled F-actin solutions.
We measure the viscoelasticity of entangled F-actin over length scales between 1 and 100 microm using one- and two-particle microrheology, and directly identify two distinct microscopic contributions to the elasticity. Filament entanglements lead to a frequency-independent elastic modulus over an extended frequency range of 0.01-30 rad/sec; this is probed with one-particle microrheology. Longitudinal fluctuations of the filaments increase the elastic modulus between 0.1 and 30 rad/sec at length scales up to the filament persistence length; this is probed by two-particle microrheology.
Gardel
M L
ML
Department of Physics & DEAS, Harvard University, Cambridge, Massachusetts 02138, USA.
Valentine
M T
MT
Crocker
J C
JC
Bausch
A R
AR
Weitz
D A
DA
D008841:Actin Cytoskeleton / Q000737:chemistry; D000199:Actins / Q000737:chemistry*; D004548:Elasticity; D012212:Rheology / Q000379:methods; D012996:Solutions; D014783:Viscosity
D000199:Actins; D012996:Solutions