Trajectory angle determination in one dimensional single molecule tracking data by orthogonal regression analysis
Trajectory angle determination in one dimensional single molecule tracking data by orthogonal regression analysis
复制标题
DOI：
10.1039/c0cp01581d
复制
发表时间：
2011-01-01
影响因子：
3.3
通讯作者：
Higgins, Daniel A.
中科院分区：
文献类型：
--
作者：
Khanh Hoa Tran Ba;Everett, Thomas A.;Higgins, Daniel A.
报道了用正交回归分析定量评价单分子扩散轨迹的方法。这种分析广泛适用于任何单粒子跟踪实验，其中沿一维（1D）扩散是预期的。它提供了一维轨迹（平面内）方向的定量数据，从而可以确定它们的绝对方向。直方图描述了轨迹角度的分布，为轨迹对齐程度提供了新的物理见解，并通过推断，材料顺序。给出了轨迹角误差和粒子沿各轨迹定位误差的估计。并与单步测角结果进行了比较。该方法的优点包括其简单和计算效率，以及客观区分1D和2D/固定轨迹的能力。通过宽视场荧光显微镜对表面活性剂模板化介孔二氧化硅薄膜中单分子扩散轨迹的分析，证明了其实用性。获得的轨迹角度直方图提供了不同种群和样本区域的平均轨迹方向和轨迹对齐程度的定量数据。通过顺序参数< P > = 2 < cos(2)(Delta theta)> - 1，从四个代表性样本区域中的每个区域的单个轨迹角度计算，定量评估介孔顺序。结果描述了有序结构域的存在（从微米到几十微米的大小），所有的< P >近似于0.9。后者对应于每个区域中单个轨迹与平均轨迹（和介孔）方向的平均偏差约为14度。
The quantitative assessment of single molecule diffusion trajectories by orthogonal regression analysis is reported. This analysis is broadly applicable to any single particle tracking experiments in which diffusion along one dimension (1D) is expected. It affords quantitative data on the (in plane) orientation of 1D trajectories, allowing for their absolute orientations to be determined. Histograms depicting the distribution of trajectory angles provide new physical insights into the degree of trajectory alignment, and by inference, materials order. Estimates of the errors in the trajectory angle and particle positioning along each trajectory are also obtained. The angle results are compared to those from single-step angle determinations. The advantages of the regression method include its simplicity and computational efficiency, and the ability to objectively differentiate between 1D and 2D/immobile trajectories. Its utility is demonstrated through analysis of single molecule diffusion trajectories in surfactant-templated mesoporous silica films as probed by wide-field fluorescence microscopy. The trajectory angle histograms obtained provide quantitative data on mean trajectory orientation and the degree of trajectory alignment in distinct populations and sample regions. Mesopore order was quantitatively assessed by implementation of an order parameter, < P > = 2 < cos(2)(Delta theta)> - 1, calculated from the individual trajectory angles in each of four representative sample regions. The results depict the presence of well-ordered domains (from microns to tens of microns in size), all having < P > approximate to 0.9. The latter corresponds to an approximate to 14 degrees average deviation of the individual trajectories from the mean trajectory (and mesopore) orientation in each domain.