Figure 1.

Magnetic Deposition Microscopy (MDM) Assembly. The MDM assembly (Panel A) is comprised of a syringe pump with adjustable flow rate (1), two valves (2) with outlets (3) to regulate flow and for air-free filling of the channels, the magnet with the flow chamber (5) and an outlet for the effluent cell suspension (6). PTFE tubing (4) is used to connect the different components. An enlarged view of the MDM device (Panel B) showing the flow channel formed between a top acrylic platen and bottom polymer slide, separated by a silicon rubber spacer. This assembly is fixed to a magnet by four retaining screws. The figure also shows portals through which cell suspensions enter and leave the flow chamber, and magnetic bars separated by two inter-polar gaps (dark gray). The schematic diagram of the MDM cell deposition section (Panel C) illustrates the force vectors acting on the paramagnetic cells (F_m), and magnetic field lines (B). The field magnitude is indicated on the gray scale of the contour plot. Note paramagnetic cell concentration at the two interpolar gaps on the deposition substrate, as indicated by F_m arrows. Also indicated are the cell velocity components: magnetic field-induced velocity, u_mag, gravitational sedimentation, u_sed, and the bulk carrier fluid flow velocity, u_f (not to scale – see text for details).