Content area
Full Text
Microuid Nanouid (2013) 14:10491057 DOI 10.1007/s10404-012-1113-5
RESEARCH PAPER
Microuidic counterow centrifugal elutriation system for sedimentation-based cell separation
Tomoki Morijiri Masumi Yamada
Toshikatsu Hikida Minoru Seki
Received: 5 January 2012 / Accepted: 11 April 2012 / Published online: 30 November 2012 Springer-Verlag Berlin Heidelberg 2012
Abstract We present a centrifugal microuidic system for precise cell/particle sorting using the concept of counterow centrifugal elutriation (CCE). A conventional CCE system uses a rotor device incorporating a ow-through separation chamber, in which the balance of centrifugal and counterow drag forces exerted on particles is gradually shifted by changing the ow rate and/or the rotation speed. In the present system, both the centrifugal and the uid forces are generated through microdevice rotation in order to signicantly simplify the setup of the conventional CCE. In addition, the density gradient of the medium is employed to elute particles/cells of different sedimentation velocities stepwise from the separation chamber instead of changing the rotation speed. We successfully separated polymer particles with diameters of 1.05.0 lm using a branched loading channel for focusing particles to the center of the separation chamber. We also demonstrated the sorting of blood cells for biological applications. This system may provide a versatile means for cell/particle sorting in a general biological laboratory and function as a unit operation in various centrifugal microuidic platforms for biochemical experiments and clinical diagnosis.
Keywords Centrifugal microuidics Cell separation
Elutriation Sedimentation
1 Introduction
Cell separation is one of the most important applications of microuidic technologies, because microchannel structures are suitable for manipulating biological particulates with sizes similar to the microchannel dimensions. Various types of microuidic cell sorters have been developed that have achieved continuous cell separation using a stable laminar ow prole formed inside microchannels (Pamme 2007). Various physicochemical properties of cells were used to separate cells, such as size (Yamada and Seki 2005; Davis et al. 2006), density (Huh et al. 2007; Morijiri et al. 2011), surface markers (Nagrath et al. 2007), deformability (Hou et al. 2010), and shape (Sugaya et al. 2011). These micro-uidic cell sorters enable highly accurate cell separation in many applications, from blood cell sorting to selective enrichment/removal of stem cells or cancer cells, using relatively simple experimental operations. However, most of these techniques require the simultaneous introduction of multiple...