Wang Ru, Wang Zhuo, Millet Larry, Gillette Martha U, Levine A J, Popescu Gabriel
Quantitative Light Imaging Laboratory, Department of Mechanical and Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801,USA.
Opt Express. 2011 Oct 10;19(21):20571-9. doi: 10.1364/OE.19.020571.
We used quantitative phase imaging to measure the dispersion relation, i.e. decay rate vs. spatial mode, associated with mass transport in live cells. This approach applies equally well to both discrete and continuous mass distributions without the need for particle tracking. From the quadratic experimental curve specific to diffusion, we extracted the diffusion coefficient as the only fitting parameter. The linear portion of the dispersion relation reveals the deterministic component of the intracellular transport. Our data show a universal behavior where the intracellular transport is diffusive at small scales and deterministic at large scales. Measurements by our method and particle tracking show that, on average, the mass transport in the nucleus is slower than in the cytoplasm.
我们使用定量相成像来测量与活细胞中质量传输相关的色散关系，即衰减率与空间模式的关系。这种方法同样适用于离散和连续的质量分布，无需进行粒子跟踪。从特定于扩散的二次实验曲线中，我们提取了扩散系数作为唯一的拟合参数。色散关系的线性部分揭示了细胞内运输的确定性成分。我们的数据显示出一种普遍行为，即细胞内运输在小尺度上是扩散性的，在大尺度上是确定性的。我们的方法和粒子跟踪测量表明，平均而言，细胞核中的质量传输比细胞质中的慢。
