Optical trapping of amyloid fibrils of hen egg-white lysozyme

We demonstrate optical trapping of protein amyloid fibrils with the use of a tightly focused laser beam. Amyloid fibrils are prepared by incubating a solution of hen egg-white lysozyme under the heating condition and characterized by atomic force microscopy. Upon the focused laser irradiation, amyloid fibrils are attracted toward the laser focus and stably trapped there. After switching off the laser, the trapped amyloids start diffusion to the surrounding solution. Thus, optical force is effectively exerted on protein amyloid fibrils and useful to trap, assembly, and manipulate them.