Pan T, helper, and cytotoxic lymphocytes were isolated from the human
peripheral blood mononuclear cell fraction by antibody staining, ferri
tin labeling, and deposition on glass slides. Two distinct forms of fe
rritin were used: one was native horse spleen ferritin, and the other
was magnetoferritin, Magnetoferritin was obtained by reconstituting th
e horse spleen ferritin iron core with superparamagnetic magnetite ins
tead of the usual paramagnetic ferrihydrite crystal, The cell depositi
on on microscopic glass slides in the magnetic held was obtained by an
instrument that was adapted from an industrial magnetic deposition an
alyzer, the ferrograph, The identity of cells in the magnetic deposits
was confirmed by comparing the cell fractions in the feed and in the
eluate with the use of now cytometry, The immunostaining protocol ampl
ified the number of ferritin molecules per cell surface antigen 20-70
times, Magnetoferritin, but not native ferritin, imparted a sufficient
magnetic moment to cells to deplete the labeled cell population betwe
en 67 and 88% of its initial concentration in a magnetic field of 1.67
Tesla (T), a field gradient of 2.57 T/mm, and a now rate of 0.01 ml/m
in, This study showed that the magnetic moment of magnetoferritin was
sufficient for immunomagnetic isolation of lymphocytes from mononuclea
r cell preparations in the modified ferrograph. (C) 1996 Wiley-Liss, I
nc.