Calibration of optical tweezers with non-spherical probes via high-resolution detection of Brownian motion

Abstract Optical tweezers are commonly used and powerful tools to perform force measurements on the piconewton scale and to detect nanometer-scaled displacements. However, the precision of these instruments relies to a great extent on the accuracy of the calibration method. A well-known calibration procedure is to record the stochastic motion of the trapped particle and compare its statistical behavior with the theory of the Brownian motion in a harmonic potential. Here we present an interactive calib... Title of program: PFMCal Catalogue Id: AEXH_v1_0 Nature of problem Calibration of optical tweezers by measuring the Brownian motion of the trapped object. The voltage-to-displacement ratio of the detection system (the inverse of the sensitivity), the stiffness of the trap and the size of the bead are obtained via the simultaneous fitting of the power spectral density (PSD), mean square displacement (MSD) and velocity autocorrelation (VAF) functions calculated from the trajectory. The calibration can be performed for non-spherical probes as well. Versions of this program held in the CPC repository in Mendeley Data AEXH_v1_0; PFMCal; 10.1016/j.cpc.2015.06.024 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)摘要：光学镊子（Optical tweezers）是一类应用广泛且性能优异的工具，可实现皮牛（piconewton）量级的力检测与纳米级位移测量。然而，该类仪器的精度高度依赖校准方法的准确性。目前主流的校准流程为：记录被捕获粒子的随机运动，并将其统计特性与简谐势（harmonic potential）下的布朗运动（Brownian motion）理论进行比对。在此，我们推出一款交互式校准[原文未完结]。 程序名称：PFMCal 目录编号：AEXH_v1_0 问题本质：通过测量被捕获物体的布朗运动完成光学镊子的校准。通过对粒子轨迹计算得到的功率谱密度（Power Spectral Density, PSD）、均方位移（Mean Square Displacement, MSD）与速度自相关（Velocity Autocorrelation, VAF）函数进行联合拟合，可获取检测系统的电压-位移比（即灵敏度的倒数）、光阱刚度以及微球尺寸。该校准方法同样支持非球形探针的校准。 Mendeley数据中的CPC仓库存储的该程序版本：AEXH_v1_0；PFMCal；DOI:10.1016/j.cpc.2015.06.024 本程序源自贝尔法斯特女王大学托管的CPC程序库（1969-2018）。