一种高精度的荧光单分子纳米级定位算法

A High Precision Algorithm for Fluorescence Single Molecule Localization with Nanometer Accuracy

荧光成像系统的技术指标、采集的荧光图像信噪比和单分子定位算法是影响单分子定位精度的3大因素.在介绍单分子定位的基本极限精度和理论计算精度的基础上,提出了一种被称为图像去噪高斯掩膜算法的单分子定位算法.依据实验用单分子成像系统的具体配置,通过计算机仿真表明,该算法良好的去噪处理和高斯加权质心运算方式,不仅能实现纳米级的定位精度,而且能突破一般理论计算精度的限制,接近基本极限精度,特别是在背景噪声较大的情况下,其优势更加明显.这对单分子的精确定位和跟踪、扩散方式分析、转移速率计算等具有重要的意义.

The fluorescence imaging system configuration,signal to noise ratio（SNR） of the collected fluorescence images and single molecule localization algorithm are the three key factors in determining the precision of single molecule localization.A single molecule localization algorithm with image de-noising and Gaussian mask was presented in this paper on the basis of a detailed description of the fundamental limit precision and theoretical calculation precision of single molecule localization.Computer simulation was conducted according to the configuration of experimental single molecule imaging system,which indicated that the proposed algorithm could not only return the positions in nanometer resolution,but also breach the limit of theoretical calculation accuracy and approach to the fundamental limit.The algorithm performed quite well in de-noising and Gaussian weighted centroid calculation over the tested SNRs,especially in the case of heavy background noises.The algorithm is of great significance for single molecule precise positioning and tracking,diffusion analysis,transportation velocity computation and so on.