在活体细胞内研究其亚细胞结构以及细胞器和分子之间或不同分子之间的相互作用过程是目前生命科学研究的主要挑战，而发展一种能够实时检测完整细胞内多个生物分子随时空变化的单分子探测和追踪技术对于研究生命过程中的分子机制具有重要意义。设计并搭建了基于变形光栅和双螺旋点扩展函数的显微成像系统，实现了在三维空间内扩展景深和纳米定位功能，极大地扩展了成像深度。通过模拟分析，该系统在高定位精度下可实现12 μm厚样品的动态探测，并实现了完整活细胞中动态粒子的实时定位和追踪。

One major challenge of the life-science research is to study the subcellular structure and the interactions among organelles and molecules or different molecules in vivo. To develop a single molecule detection and tracking technology, which can real-time detect multiple biomolecules in living cells, is significant to the study on the molecular mechanism of the life process. We design and establish a microscopy imaging system based on the distorted grating and the double helix point spread function technologies, which can extend the depth of field and reach nano-positioning in three-dimensional space. The simulational results show that the system can achieve dynamic detection the 12 μm-depth sample with high localization accuracy. And the real-time positioning and tracking of dynamic biomolecules in living cells is achieved experimentally.