Journal of Magnetism and Magnetic Materials 194 (1999) 224—230
Continuous cell separation using novel magnetic quadrupole
flow sorter
Maciej Zborowski!,*, Liping Sun", Lee R. Moore!, P. Stephen Williams!,
Jeffrey J. Chalmers"
!Department of Biomedical Engineering, The Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44195-5254, USA
"Department of Chemical Engineering, The Ohio State University, 121 Koffolt Laboratories, 140 West 19th Street, Columbus,
OH 43210-1180, USA
Abstract
A laboratory prototype of a flow cell sorter based on magnetic quadrupole field was built and evaluated. The magnetic
force acting on magnetically labeled cells in such a field has a ‘centrifugal’ character which provides a basis for the design
of a continuous separation process. The sorter was tested on a model cell system of human peripheral lymphocytes
labeled with magnetic colloid. ( 1999 Published by Elsevier Science B.V. All rights reserved.
Keywords: Quadrupole field; Magnetic colloid; Immunomagnetic separation; Cell separation; Human lymphocytes
Rapid cell sorting is important in the newly de-
veloping fields of cellular therapy and in bio-
technology. Current clinical devices are based
on immunoaffinity columns, or on high-gradient
magnetic separation (HGMS) columns utilizing
either micrometer-sized polymeric beads doped
with magnetite, or nanometer-size iron-dextran
colloids, conjugated to targeting antibodies [1—3].
We are interested in the development of a fast,
continuous process of cell separation based on
monoclonal antibodies, magnetic colloid, and
a flow field in an open-gradient magnetic field. The
continuous separation process offers advantages in
the ability to process large cell volumes, use of
*Corresponding author. Fax: #1-216-444-9198; e-mail:
zborow@bme.ri.ccf.org.
on-line monitoring of the separation process, and
ability to stage and recirculate sorted fractions. The
challenges include exact control over forces in-
volved in displacement of the labeled cell popula-
tion from the unlabeled population t