“…Briefly, microfluidic channels can be functionalized with affinity biomolecules and, similar to the initial work by Wigzell et al (Wigzell and Andersson, 1969), cells can be selectively captured from a flow channel (Didar and Tabrizian, 2010). Numerous examples exist in the literature that have illustrated the effectiveness of microfluidic cell affinity chromatography for the isolation of circulating tumor cells (Gleghorn et al, 2010, Stott et al, 2010a, Nagrath et al, 2007, Adams et al, 2008a, Du et al, 2006), endothelial progenitor cells (Hansmann et al, 2011, Plouffe et al, 2009b, Hatch et al, 2011, Hatch et al, 2012), endothelial and smooth muscle cells (Plouffe et al, 2009b, Green and Murthy, 2009, Plouffe et al, 2007, Plouffe et al, 2008), skin stem cells (Zhu et al, 2013), white blood cells (Murthy et al, 2004, Sin et al, 2005, Xu et al, 2009). Although microfluidic capture channels have illustrated excellent recoveries (> 90%) and purities (> 95%) (Didar and Tabrizian, 2010) of very rare cells versus many alternative approaches the difficulty in gently removing trapped cells from the surface of the affinity substrate has limited the use in many biological fields (Murthy and Radisic, 2008).…”