Michalet Xavier, Berglund Andrew J
Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California 90095, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Jun;85(6 Pt 1):061916. doi: 10.1103/PhysRevE.85.061916. Epub 2012 Jun 21.
Single-particle tracking is increasingly used to extract quantitative parameters on single molecules and their environment, while advances in spatial and temporal resolution of tracking techniques inspire new questions and avenues of investigation. Correspondingly, sophisticated analytical methods are constantly developed to obtain more refined information from measured trajectories. Here we point out some fundamental limitations of these approaches due to the finite length of trajectories, the presence of localization error, and motion blur, focusing on the simplest motion regime of free diffusion in an isotropic medium (Brownian motion). We show that two recently proposed algorithms approach the theoretical limit of diffusion coefficient uncertainty. We discuss the practical performance of the algorithms as well as some important implications of these results for single-particle tracking.
单粒子追踪越来越多地用于提取关于单分子及其环境的定量参数，而追踪技术在空间和时间分辨率方面的进展激发了新的问题和研究途径。相应地，不断开发复杂的分析方法以从测量轨迹中获得更精确的信息。在这里，我们指出由于轨迹长度有限、存在定位误差和运动模糊，这些方法存在一些基本限制，重点关注各向同性介质中自由扩散的最简单运动模式（布朗运动）。我们表明，最近提出的两种算法接近扩散系数不确定性的理论极限。我们讨论了算法的实际性能以及这些结果对单粒子追踪的一些重要影响。
