FACS analysis of cells with ab18051.HEK 293T cells (5 x 105) were mock transfected (thin line) or transfected with an expression plasmid enabling surface expression of the TNFR homology domain of human OPG (thick line). Cells were incubated on ice for 30 min in 50µl FACS buffer (PBS, 5% fetal calf serum, 0.02% azide)containing 1µg/ml of ab18051. After washing in FACS buffer, R-PE-conjugated antibody to rat IgG was added. Cells were incubated on ice for 30 min, washed and then analyzed by Flow Cytometry.