Controlling Brownian motion of single protein molecules and single fluorophores in aqueous buffer
Controlling Brownian motion of single protein molecules and single fluorophores in aqueous buffer
复制标题
DOI：
10.1364/oe.16.006941
复制
发表时间：
2008-05-12
期刊：
影响因子：
3.8
通讯作者：
Moerner, W. E.
中科院分区：
文献类型：
--
作者：
Cohen, Adam E.;Moerner, W. E.
我们提出了一种反布朗电动陷阱(Abel Trap)，能够在水溶液中捕获单个荧光标记的蛋白质分子。阿贝尔陷阱的工作原理是跟踪单个荧光粒子在溶液中的布朗运动，并施加一个随时间变化的电场，该电场旨在诱导一个电动漂移来抵消布朗运动。Abel陷阱的捕获强度受到反馈环路延迟的限制。在以前版本的陷阱中，此延迟由用于视频跟踪的摄像头的有限帧速率设置。在目前的系统中，粒子的运动完全在硬件中跟踪(没有相机或图像处理软件)，使用快速旋转的激光焦点和锁定检测。反馈延迟由光子到达的有限速率设置。我们展示了在缓冲液中捕获蛋白质GroEL的单个分子，以及我们展示了染料Cy3在水中的单个荧光团的限制。(C)2008年美国光学学会。
We present an Anti-Brownian Electrokinetic trap (ABEL trap) capable of trapping individual fluorescently labeled protein molecules in aqueous buffer. The ABEL trap operates by tracking the Brownian motion of a single fluorescent particle in solution, and applying a time-dependent electric field designed to induce an electrokinetic drift that cancels the Brownian motion. The trapping strength of the ABEL trap is limited by the latency of the feedback loop. In previous versions of the trap, this latency was set by the finite frame rate of the camera used for video-tracking. In the present system, the motion of the particle is tracked entirely in hardware (without a camera or image-processing software) using a rapidly rotating laser focus and lock-in detection. The feedback latency is set by the finite rate of arrival of photons. We demonstrate trapping of individual molecules of the protein GroEL in buffer, and we show confinement of single fluorophores of the dye Cy3 in water. (C) 2008 Optical Society of America.