Abstract
We have been proposing cell rolling column as a label free cell separation technique, in which cells roll on the flow channel surfaces due to the interaction between cell membrane molecules and antibodies immobilized on the surface. This study was designed to investigate the effect of the antibody density on cell rolling behavior in order to achieve optimal cell separation. Induced pluripotent stem (iPS) cells were flowed on the polymer coated microfluidic channels immobilized with monoclonal antibodies to stage-specific embryonic antigen 1 (SSEA-1). Three types of poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)-co-p-nitrophenyl oxycarbonyl poly(ethylene glycol) methacrylate (MEONP)] (PMBN) with different immobilization capacity were synthesized by changing monomer feed ratios. The cell rolling rate was decreased when the shear stress was increased or the immobilized antibody density was decreased. A flow cytometry assay revealed that rolling cells expressed more SSEA-1 than floating cells, which have no interaction with antibody immobilized microfluidic surfaces.
