TY - JOUR
T1 - Immunomagnetic separation reagents as markers in electron microscopy
AU - Fisher, Phyllis J.
AU - Springett, Margaret J.
AU - Dietz, Allan B.
AU - Bulur, Peggy A.
AU - Vuk-Pavlović, Stanimir
N1 - Funding Information:
Supported by Mrs. Adelyn L. Luther, Singer Island, FL, and the Mayo Clinic Cancer Center. A.B.D. is a Glen and Florence Voyles Foundation Scholar in Stem Cell Biology. We thank Dr. Franklyn G. Prendergast for continuing interest and support.
PY - 2002/4/1
Y1 - 2002/4/1
N2 - Antibodies coupled to magnetic particles have been employed for immunomagnetic cell isolation, but their consequent use for electron microscopy (EM) has not been evaluated. We used commercial antibodies coupled to iron-dextran to isolate T cells and monocytes/macrophages by immunomagnetic adsorption from normal human peripheral blood mononuclear cells. Subsequently, we studied the association of electron-dense immunomagnetic reagents with cell membranes. CD14-positive monocytes/macrophages isolated from fixed peripheral blood mononuclear cells retained electron-dense beads on the plasma membrane, while live cells internalized them. Flow cytometry and electron microscopy measurements of the percentage of cells that bound a CD4-specific immunomagnetic reagent in pan-T cell isolates (containing numerous T cell subtypes) were indistinguishable. The immunomagnetic reagent associated with cells could be secondarily labeled by secondary antibody coupled to colloidal gold. This study shows that these reagents used for cell isolation or just labeling, remain associated with their targets at the cell membrane. Immunomagnetic reagents allow "capturing" of rare cells from complex mixtures, purifying and concentrating them in a single step for subsequent electron microscopy. The large number of commercially available immunomagnetic reagents specific for different human, mouse and rat antigens provides additional resources for visualization of cellular ultrastructure.
AB - Antibodies coupled to magnetic particles have been employed for immunomagnetic cell isolation, but their consequent use for electron microscopy (EM) has not been evaluated. We used commercial antibodies coupled to iron-dextran to isolate T cells and monocytes/macrophages by immunomagnetic adsorption from normal human peripheral blood mononuclear cells. Subsequently, we studied the association of electron-dense immunomagnetic reagents with cell membranes. CD14-positive monocytes/macrophages isolated from fixed peripheral blood mononuclear cells retained electron-dense beads on the plasma membrane, while live cells internalized them. Flow cytometry and electron microscopy measurements of the percentage of cells that bound a CD4-specific immunomagnetic reagent in pan-T cell isolates (containing numerous T cell subtypes) were indistinguishable. The immunomagnetic reagent associated with cells could be secondarily labeled by secondary antibody coupled to colloidal gold. This study shows that these reagents used for cell isolation or just labeling, remain associated with their targets at the cell membrane. Immunomagnetic reagents allow "capturing" of rare cells from complex mixtures, purifying and concentrating them in a single step for subsequent electron microscopy. The large number of commercially available immunomagnetic reagents specific for different human, mouse and rat antigens provides additional resources for visualization of cellular ultrastructure.
KW - Electron microscopy
KW - Immunomagnetic separation
KW - Monocytes
KW - T cells
KW - Ultrastructure
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U2 - 10.1016/S0022-1759(02)00007-8
DO - 10.1016/S0022-1759(02)00007-8
M3 - Article
C2 - 11983222
AN - SCOPUS:0036538276
VL - 262
SP - 95
EP - 101
JO - Journal of Immunological Methods
JF - Journal of Immunological Methods
SN - 0022-1759
IS - 1-2
ER -