Optical separation and controllable delivery of cells from particle and cell mixture

Cell separation and delivery have recently gained significant attention in biological and biochemical studies. In this work, an optical method for separation and controllable delivery of cells by using an abruptly tapered fiber probe is reported. By launching a laser beam at the wavelength of 980 nm into the fiber, a mixture of cells with sizes of similar to 5 and similar to 3 mu m and poly( methyl methacrylate) particles with size of 5 mu m are separated into three chains along the direction of propagation of light. The cell and particle chains are delivered in three dimensions over 600 mu m distance. Experimental results are interpreted by numerical simulations. Optical forces and forward migration velocities of different particles and cells are calculated and discussed.