Optical measurement of cell membrane tension.
Using a novel noncontact technique based on optical interferometry, we quantify the nanoscale thermal fluctuations of red blood cells (RBCs) and giant unilamellar vesicles (GUVs). The measurements reveal a nonvanishing tension coefficient for RBCs, which increases as cells transition from a discocytic shape to a spherical shape. The tension coefficient measured for GUVs is, however, a factor of 4-24 smaller. By contrast, the bending moduli for cells and vesicles have similar values. This is consistent with the cytoskeleton confinement model, in which the cytoskeleton inhibits membrane fluctuations [Gov et al., Phys. Rev. Lett. 90, 228101, (2003).
Popescu
Gabriel
G
George R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Ikeda
Takahiro
T
Goda
Keisuke
K
Best-Popescu
Catherine A
CA
Laposata
Michael
M
Manley
Suliana
S
Dasari
Ramachandra R
RR
Badizadegan
Kamran
K
Feld
Michael S
MS
D055592:Biophysical Phenomena; D001703:Biophysics; D048430:Cell Shape; D003599:Cytoskeleton / Q000502:physiology; D004907:Erythrocyte Deformability; D004910:Erythrocyte Membrane / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D008081:Liposomes; D008857:Microscopy, Interference; D036103:Nanotechnology; D055095:Optics and Photonics; D013102:Spherocytes / Q000502:physiology; D013500:Surface Tension
D008081:Liposomes