IMMUNOMAGNETIC ISOLATION OF MAGNETOFERRITIN-LABELED CELLS IN A MODIFIED FERROGRAPH

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.