Singer Wolfgang, Nieminen Timo A, Heckenberg Norman R, Rubinsztein-Dunlop Halina
Centre for Biophotonics and Laser Science, Department of Physics, The University of Queensland, Brisbane, Queensland 4072, Australia.
Phys Rev E Stat Nonlin Soft Matter Phys. 2007 Jan;75(1 Pt 1):011916. doi: 10.1103/PhysRevE.75.011916. Epub 2007 Jan 17.
The size of particles that can be trapped in optical tweezers ranges from tens of nanometers to tens of micrometers. This size regime also includes large single molecules. Here we present experiments demonstrating that optical tweezers can be used to collect polyethylene oxide molecules suspended in water. The molecules that accumulate in the focal volume do not aggregate and therefore represent a region of increased molecule concentration, which can be controlled by the trapping potential. We also present a model that relates the change in concentration to the trapping potential. Since many protein molecules have molecular weights for which this method is applicable the effect may be useful in assisting nucleation of protein crystals.
能够被光镊捕获的粒子大小范围从几十纳米到几十微米。这个尺寸范围还包括大的单个分子。在此，我们展示了一些实验，证明光镊可用于收集悬浮在水中的聚环氧乙烷分子。在焦点区域积累的分子不会聚集，因此代表了分子浓度增加的区域，这可以通过捕获势来控制。我们还提出了一个将浓度变化与捕获势联系起来的模型。由于许多蛋白质分子的分子量适用于此方法，这种效应可能有助于蛋白质晶体的成核。
