title: Spatial analysis of erythrocyte membrane fluctuations by digital holographic microscopy.
abstract: Red blood cell (RBC) membrane fluctuations provide important insights into cell states. We present a spatial analysis of red blood cell membrane fluctuations by using digital holographic microscopy (DHM). This interferometric and dye-free technique, possessing nanometric axial and microsecond temporal sensitivities enables to measure cell membrane fluctuations (CMF) on the whole cell surface. DHM acquisition is combined with a model which allows extracting the membrane fluctuation amplitude, while taking into account cell membrane topology. Uneven distribution of CMF amplitudes over the RBC surface is observed, showing maximal values in a ring corresponding to the highest points on the RBC torus as well as in some scattered areas in the inner region of the RBC. CMF amplitudes of 35.9+/-8.9 nm and 4.7+/-0.5 nm (averaged over the cell surface) were determined for normal and ethanol-fixed RBCs, respectively.
authors.affiliation: Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Rappaz
authors.forename: Alexander
authors.initials: A
authors.lastname: Barbul
authors.forename: Annick
authors.initials: A
authors.lastname: Hoffmann
authors.forename: Daniel
authors.initials: D
authors.lastname: Boss
authors.forename: Rafi
authors.initials: R
authors.lastname: Korenstein
authors.forename: Christian
authors.initials: C
authors.lastname: Depeursinge
authors.forename: Pierre J
authors.initials: PJ
authors.lastname: Magistretti
authors.forename: Pierre
authors.initials: P
authors.lastname: Marquet