Chang Yi-Ren, Hsu Long, Chi Sien
Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan.
Appl Opt. 2006 Jun 1;45(16):3885-92. doi: 10.1364/ao.45.003885.
Since their invention in 1986, optical tweezers have become a popular manipulation and force measurement tool in cellular and molecular biology. However, until recently there has not been a sophisticated model for optical tweezers on trapping cells in the ray-optics regime. We present a model for optical tweezers to calculate the optical force upon a spherically symmetric multilayer sphere representing a common biological cell. A numerical simulation of this model shows that not only is the magnitude of the optical force upon a Chinese hamster ovary cell significantly three times smaller than that upon a polystyrene bead of the same size, but the distribution of the optical force upon a cell is also much different from that upon a uniform particle, and there is a 30% difference in the optical trapping stiffness of these two cases. Furthermore, under a small variant condition for the refractive indices of any adjacent layers of the sphere, this model provides a simple approximation to calculate the optical force and the stiffness of an optical tweezers system.
自1986年发明以来，光镊已成为细胞和分子生物学中一种常用的操控和力测量工具。然而，直到最近，在光线光学领域还没有一个用于光镊捕获细胞的复杂模型。我们提出了一个光镊模型，用于计算作用在代表普通生物细胞的球对称多层球体上的光力。该模型的数值模拟表明，不仅作用在中国仓鼠卵巢细胞上的光力大小比作用在相同尺寸聚苯乙烯珠上的光力大小显著小三倍，而且作用在细胞上的光力分布也与作用在均匀粒子上的光力分布有很大不同，并且这两种情况下光镊捕获刚度相差30%。此外，在球体任意相邻层折射率的小变化条件下，该模型提供了一种简单的近似方法来计算光镊系统的光力和刚度。
