Magnetic Cell Manipulation and Sorting

Cell manipulation is one of the fastest growing segments of biotechnology engineering, and magnetic cell separation plays a large part in its development. Because of low magnetic permeability of biological materials, the magnetostatic forces can be made to operate highly selectively on cells tagged with magnetic nanoparticles, with no interference from the physiological electrolyte solutions used for cell suspension and from other cells. The increasing availability of inexpensive permanent magnet blocks capable of generating fields in excess of 1 tesla (T) and gradients up to 1000 T/m combined with a large selection of targeting antibodies against nearly all cell surface markers of interest in clinical and laboratory applications, together with high-quality superparamagnetic iron oxide nanoparticles, makes magnetic separation an appealing alternative to other cell separation methods, including centrifugation and fluorescence-activated cell sorting. This chapter provides a brief overview of the underlying physical principles and a number of examples selected from a large body of scientific literature published on the subject.