Duong Nghia Tuan, Yamato Masanori, Nakano Masayuki, Kume Satoshi, Tamura Yasuhisa, Kataoka Yosky, Wong Alan, Nishiyama Yusuke
Advanced Solid-State NMR Unit, RIKEN CLST-JEOL Collaboration Center, RIKEN, Yokohama, Kanagawa 230-0045, Japan.
Multi-Modal Microstructure Analysis Unit, RIKEN CLST-JEOL Collaboration Center, RIKEN, Kobe, Hyogo 650-0047, Japan.
Molecules. 2017 Aug 3;22(8):1289. doi: 10.3390/molecules22081289.
Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical technique and has been widely used in metabolomics. However, the intrinsic low sensitivity of NMR prevents its applications to systems with limited sample availabilities. In this study, a new experimental approach is presented to analyze mass-scarce samples in limited volumes of less than 300 nL with simple handling. The sample is loaded into the glass capillary, and this capillary is then inserted into a Kel-F rotor. The experimental performance of the capillary-inserted rotor (capillary-insert) is investigated on an isotropic solution of sucrose by the use of a high-resolution micro-sized magic angle spinning (HRµMAS) probe. The acquired NMR signal's sensitivity to a given sample amount is comparable or even higher in comparison to that recorded by the standard solution NMR probe. More importantly, this capillary-insert coupled with the HRµMAS probe allows in-depth studies of heterogeneous samples as the MAS removes the line broadening caused by the heterogeneity. The NMR analyses of mass-limited cultured neurospheres have been demonstrated, resulting in high quality spectra where numerous metabolites are unambiguously identified.
核磁共振（NMR）光谱是一种强大的分析技术，已广泛应用于代谢组学。然而，NMR固有的低灵敏度限制了其在样品量有限的系统中的应用。在本研究中，提出了一种新的实验方法，用于以简单的操作分析体积小于300 nL的微量样品。将样品装入玻璃毛细管中，然后将该毛细管插入凯尔氟转子中。使用高分辨率微型魔角旋转（HRµMAS）探头，在蔗糖的各向同性溶液上研究插入毛细管的转子（毛细管插入物）的实验性能。与标准溶液NMR探头记录的信号相比，所采集的NMR信号对给定样品量的灵敏度相当甚至更高。更重要的是，这种与HRµMAS探头结合的毛细管插入物能够对异质样品进行深入研究，因为魔角旋转消除了由异质性引起的谱线展宽。已证明对质量有限的培养神经球进行了NMR分析，从而得到了高质量的光谱，其中可明确鉴定出许多代谢物。
