Chimeric E-selectin–IgG2a binds to subsets of CD34⁺ cells. Soluble E-selectin–IgG2a chimera was used to quantify the number of ESL-expressing CD34⁺immediately after purification from CB. Using FACS analysis, 75% ± 5% of CD34⁺ cells bind to E-selectin–IgG2a chimeric molecule (B) (N = 3). The binding of E-selectin/IgG2a was dependent on divalent cations and was inhibited in the presence of 2 mmol/L EDTA (B). Endothelial cells that do not express FucT-VII showed no binding to the soluble E-selectin–IgG chimera (C). Freshly isolated CD34⁺ cells do not express CD15 (A). Agarose and LTC-IC assays performed on CD34⁺ cells bound to soluble E-selectin chimera showed a 2.09 ± 0.58-fold higher progenitor (D) and 14.9- ± 10.7-fold higher LTC-IC content than the population that did not bind to soluble E-selectin chimera (E). The CD34⁺cells that failed to bind to E-selectin were virtually devoid of CD34⁺ cells with LTC-IC potential (E) (N = 3, P< .05).