Attachment of erythroblasts to transfected and nontransfected HeLa cells. Early erythroblasts were cultured with HeLa cells transfected with the full-length (Emp-1) plasmid (A through F), with the truncated (Emp-2) plasmid (H), or with nontransfected HeLa cells (G) for 3 to 4 days. On day 3 or 4, floating cells were removed and the adherent cells were washed two times to remove any trapped nonadherent cells. Cells adhering on the petri dishes were fixed and stained with Wright-Giemsa without detaching from the dishes and examined by bright-field microscopy. Original magnification: (A through F) × 100; (G and H) × 40.