Immunofluorescence staining with CD164 and erythroid specific MoAbs of cord blood CD34⁺ cells cultured under erythroid conditions. CD34⁺ cells were isolated from cord blood and cultured for 5 to 9 days under the conditions described. Cultured cells were cytocentrifuged, fixed in acetone, and stained by dual immunofluorescence using DAPI as a nuclear counterstain. Of interest are day-5 cultured cells stained in the Golgi region with 103B2/9E10 (A) and105A5 (B) antibodies. These cells were negative with anti-glycophorin C (C). Similar staining was obtained for day-9 cultured cells using 103B2/9E10 (D). Also shown are day-9 cells labeled with an IgG₃ irrelevant isotype-matched negative control (E), anti–glycophorin C (F), anti–glycophorin A (G), and band III (H); and day-6 cultured cells labeled with 103B2/9E10 plus FITC–anti-mouse IgG₃ (I through K) and glycophorin C (I), glycophorin A (J), or band III (K) plus Texas Red–anti-mouse IgG₁. Arrow heads indicate double-stained cells and arrows show cells stained only with 103B2/9E10 (I through K); (A through H: 40 × original magnification; I through K: 100 × original magnification).