Autologous Bone Marrow Transplantation - Blog Science Connections

Magnetic Affinity Colloid Elimination of Specific
Cell Populations From Bone Marrow
Christopher L Reading, Weiben Yong, Edward D. Ball,
and Karel A. Dicke
We have previously described the use of a colloidal magnetic fluid for removing
monoclonal antibody-defined cell populations from marrow aspirates used for
autologous transplantation (1-4). We describe here the development of an
avidin-based magnetic affinity colloid (MAC) capable of eliminating 4-5 logs of
specific cell populations reactive with monoclonal antibodies (MAbs) and
lectins. We have also phenotyped a number of cell samples from patients with
acute leukemia and defined cocktails of MAbs and soybean agglutinin that are
highly reactive with fresh blasts. In addition to eliminating clonogenic cells from
experimental mixtures with normal bone marrows, we have also removed
clonogenic leukemia cells from fresh peripheral blood or marrow samples from
patients with acute leukemia who were in relapse.
MATERIALS AND METHODS
Reducing cobaltous chloride with sodium borohydride to form a colloidal
suspension has been described before (1,2,4), and the details of MAC
production are the subject of another communication (Christopher L. Reading
et al, unpublished manuscript). In brief, a solution containing a cobalt-citrate
complex is added to a solution containing sodium borohydride to form nuclei of
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