A new technique of cell micropatterning was presented. Mouse osteoblast cells (MC3T3-E1)were seeded on a substrate whose surface was exposed to a periodically modulated magnetic field (a line pattern with a 200- or 600-mum pitch) produced by a field modulator inserted into a homogeneous magnetic field of 1 T generated by an electromagnet. The cells were trapped consistent with the line profile of the modulated field. The trapping efficiency was enhanced by adding Mn(II)EDTA (paramagnetic) to the cultivation medium. The cells were subsequently incubated in the magnetic field. The same technique was applied to whole blood to pattern red blood cells.