Nanopore Instrument for Analyzing Single Polymer Molecules in Solution

表征单个原子和分子的仪器在生物和物理科学中有着广泛的应用，在微型机器和电子设备的制造技术中起着重要的作用。除了光学显微镜外，所有这些仪器都是用固体分子或栓系分子，没有一种仪器能够分析溶液中大量的单个聚合物分子。最近的研究表明，在不透水的膜上，基于纳米大小的孔（纳米孔），有可能开发出具有这种能力的仪器。孔的直径允许像DNA这样的聚合物通过，但一次只能通过一个。这些现有的实验探测器采用人工脂质膜，由α溶血素（一种天然存在的蛋白质毒素）形成毛孔。DNA分子通过这些孔隙时的特性测量表明，单个分子的长度可以快速而可靠地确定。迄今为止，由于制备膜的困难以及膜的脆弱性和寿命短，这些实验仪器的使用受到限制。该奖项为开发一种新型纳米多孔膜提供了支持，这种膜可以作为α溶血素膜的强大替代品。将探索几种从云母中生产新膜的策略，包括使用辐射和酸蚀刻。云母基膜在工作中应该是非常稳定的。一项成功的努力很可能导致开发出一种能够快速测量混合群体中发现的单个DNA分子长度和数量的仪器，并且有可能开发出一种无需化学或放射性标记程序即可对长DNA进行快速测序的仪器。

Instruments for characterizing individual atoms and molecules have extensive applications in the biological and physical sciences, and play an important role in manufacturing techniques for miniature machines and electronic devices. With the exception of the light microscope, all such instruments work with solid or tethered molecules, and none have the capacity to analyze large numbers of single polymer molecules in solution. Recent work has shown the potential for development of instruments with such capability that are based on nanometer-sized pores (nanopores) in otherwise impermeable membranes. The diameter of the pore permits passage of polymers like DNA, but only one at a time. These existing experimental detectors employ artificial lipid membranes with pores formed by alpha-hemolysin, a naturally occurring proteinaceous toxin. Measurement of the properties of DNA molecules as they transit such pores has shown that the length of individual molecules can be determined rapidly and reliably. To date, these experimental instruments have had limited use because of the difficulty of preparing the membranes and because of the membrane's fragility and short lifetime. This award provides support for development of a new type of nanoporous membrane that can be used as a robust replacement for the alpha-hemolysin membranes. Several strategies to produce the new membranes from mica will be explored, including the use of radiation followed by an acid etch. Mica-based membranes should be exceedingly stable in operation. A successful effort is likely to lead to development of an instrument capable of rapid measurement of the length and number of individual DNA molecules found in mixed populations, and, potentially, to development of an instrument that can perform rapid sequencing of long DNAs without the need for chemical or radioactive labeling procedures.