梯度场中荧光关联谱测量的Monte Carlo模拟

Monte Carlo Simulation of FCS in a Laser Gradient Field

荧光关联谱 (FCS)利用少量分子的荧光涨落获得分子运动和反应信息 ,是一种探测活细胞内生物过程的有力工具。本文利用MonteCarlo方法模拟激光梯度场下瑞利粒子的布朗运动 ,分析梯度场对FCS测量得到的扩散时间、粒子数等参数的影响 ,模拟与初步实验结果定性吻合。

Fluorescence correlation spectroscopy (FCS) is a powerful tool for probing biological process inside living cells. It measures fluorescence fluctuations of small number of molecules and derive information on molecular kinetics and reactions. We have developed a Monte Carlo model to simulate Browning motion of Rayleigh particles in a laser gradient field. The simulation reveals relations between laser field strength and measured parameters from FCS, such as diffusion coefficient and number density of the particles. The simulated results agree qualitatively to the experimental results obtained using fluorescent spheres. Empirical relations from the simulation are also discussed.