Light-induced cell separation in a tailored optical landscape

Abstract

We demonstrate passive optical sorting of cell populations in the absence of any externally driven fluid flow. Specifically, we report the movement of erythrocytes and lymphocytes in an optical landscape, consisting of a circularly symmetric light pattern created by a Bessel light beam. These distinct cell populations move, spontaneously and differentially, across the underlying periodic optical landscape. Thus, we were able to separate lymphocytes from a mixed population of cells containing erythrocytes and then collect the lymphocytes in a microcapillary reservoir. We also demonstrate an enhanced form of this separation that exploits the polarizability of silica microspheres by attaching spheres coated with antibodies to cell surface markers to a subpopulation of lymphocytes. These techniques may be applied using standard laboratory apparatus.

Optical tweezers for single cells

“…The Bessel beam has been used for flow-free optical separation of lymphocytes from erythrocytes (Paterson et al 2005) using its unique optical landscape, which has been discussed in §2.3.1. When higher power was used, the biconcave-shaped erythrocytes locked into outer rings of the Bessel beam (third, fourth and fifth), while spherically shaped lymphocytes rapidly moved directly to the beam centre and they were collected from the centre core.…”

“…Microfluidic channels offer a fluid flow system with sample volume as small as the order of a few nanolitres where cells can be transported, manipulated, sorted and isolated with their surrounding media. OT as an important contactfree cell-friendly manipulation tool have been integrated with microfluidic devices Paterson et al 2005;Wang et al 2005;Jess et al 2006;Monat et al 2008). …”

Tunable generation of Bessel beams with a fluidic axicon

“…In addition, the concentric rings of light associated with the transverse intensity profile have been used to enable the static optical sorting of both silica microspheres, as a function of size 7 and human blood cells, as a function of shape. 8 Experimentally, Bessel beams can be generated through the illumination of an axicon with a monochromatic plane wave. 9 An axicon can be thought of as a cone-shaped prism and is typically characterized by the angle ␥, as defined in Fig.…”

Optoelectronic Tweezers for the Manipulation of Cells, Microparticles, and Nanoparticles

“…Optical tweezers provides dynamic, flexible manipulation of specific single cells. Optical tweezers uses the gradient force of light to trap particles using a highly-focused laser beam (Ashkin et al, 1986), and has been used in many research applications, such as measuring cell motility (Maier et al, 2004), sorting colloidal particles (MacDonald et al, 2003), sorting cells (Paterson et al, 2005), and trapping and assembling nanowires (Pauzauskie et al, 2006). In addition, the basic single-beam optical trap has been extended to multiple traps from a single laser source using holographic imaging (Grier, 2003), evanescent-wave traps , and plasmonic-enhanced traps (Miao & Lin, 2007;Grigorenko, et al, 2008).…”