Calculation of spherical red blood cell deformation in a dual-beam optical stretcher

Abstract

We present a numerical method based on the linear elastic membrane theory to compute the morphological deformation of a spherical cell from the photonics stress distribution over the cellular membrane. The method is applied to fit the experimental data for deformation of a spherical human red blood cell trapped and stretched in a fiber-optical dual-beam trap with a single fitting parameter Eh where E is the Young's modulus of elasticity and h is the thickness of the cell membrane. We obtained Eh = (20+/-2)muNm(-1) which is comparable to results reported earlier. This numerical method can be applied in general experimental conditions.

Optical tweezers for single cells

“…Guck et al (2000) calculated the stress distribution generated from two divergent counterpropagating beams around a single cell but the cell deformation was obtained from experimental measurements. Dao et al (2003), Lim et al (2004a) and Liu et al (2006) presented numerical simulations, based on mechanical models for two-bead attached RBCs, while Bareil et al (2006) numerically simulated the deformation of RBCs by OS. A model using the concept of Euler buckling instability has been used to capture the essential physics of RBC folding in an optical trap (Ghosh et al 2006).…”

Effect of N‐ethylmaleimide, chymotrypsin, and H2O2 on the viscoelasticity of human erythrocytes: Experimental measurement and theoretical analysis

“…Several methods have been developed to apply an external force to a biological cell either locally or distributed over the cell to probe its mechanical response [3][4][5][6][7][8][9][10][11][12][13][14][15][16]. These methods include optical magnetic twisting cytometry [3], optical tweezers with micro-beads (serving as handles) attached to RBCs [4,[12][13][14], optical tweezers dragging RBCs through viscous fluid [5], dual-trap optical tweezers [6], optical stretcher [7][8][9], micropipette aspiration [10,11], RBC bending and relaxation via optical tweezers with triple-focal spots [15], and the RBC deformation and relaxation in a parallel-plate flow chamber [16]. Each of these methods has certain advantages and limitations, and often complements each other.…”

Optical tweezers technique for the study of red blood cells deformation ability

“…All these factors simplify mathematical formalization and simulation, and this is one of the reasons why red blood cells are so often 1 The article is published in the original. used for estimation of a dragging force of the traps [13,14].…”

“…A large number of works [12][13][14][15][16][17][18][19][20][21][22][23] is dedicated to the RBCs study. Tensile [12,13,16] and bend [12,20] deformation modes were implemented for measure ment of elasticity modulus [17,22], membrane viscos ity parameters [17], shear modulus [18] and some other characteristics. The reports on measurements of erythrocytes adhesion force [12,23] and studies of the mechanisms of adhesion with laser tweezers using either single beam [12 and references therein] or dual trap configurations [13 and references therein] are available.…”