RIKEN Quantitative Biology Center, Osaka, Japan.
Biophys J. 2013 Aug 6;105(3):555-64. doi: 10.1016/j.bpj.2013.07.001.
Single particle tracking is widely used to study protein movement with high spatiotemporal resolution both in vitro and in cells. Quantum dots, which are semiconductor nanoparticles, have recently been employed in single particle tracking because of their intense and stable fluorescence. Although single particles inside cells have been tracked in three spatial dimensions (X, Y, Z), measurement of the angular orientation of a molecule being tracked would significantly enhance our understanding of the molecule's function. In this study, we synthesized highly polarized, rod-shaped quantum dots (Qrods) and developed a coating method that optimizes the Qrods for biological imaging. We describe a Qrod-based single particle tracking technique that blends optical nanometry with nanomaterial science to simultaneously measure the three-dimensional and angular movements of molecules. Using Qrods, we spatially tracked a membrane receptor in living cells in four dimensions with precision close to the single-digit range in nanometers and degrees.
单颗粒示踪技术被广泛应用于在体外和细胞内进行高时空分辨率的蛋白质运动研究。由于具有高强度和稳定的荧光，最近量子点（半导体纳米粒子）已被应用于单颗粒示踪技术。尽管已经在三个空间维度（X、Y、Z）中跟踪了细胞内的单个颗粒，但对被跟踪分子的角向取向的测量将显著增强我们对分子功能的理解。在这项研究中，我们合成了高度各向异性的棒状量子点（Qrods），并开发了一种涂层方法，优化了量子点用于生物成像。我们描述了一种基于 Qrod 的单颗粒跟踪技术，该技术将光学纳米技术与纳米材料科学相结合，以同时测量分子的三维和角向运动。使用 Qrods，我们在活细胞中以接近纳米和角度的个位数精度在四个维度上对膜受体进行了空间跟踪。
