Small proportion of CD34 purified from human tonsils binds to L-selectin and is MECA-79 positive. (A) Calibration of L-selectin affinity column using radiolabeled synthetic glyco(sulfo)peptides modeled after N-terminus of human PSGL-1. Fractions 1 to 20 were collected using 20 mM Tris-HCl, pH 7.5, 50 mM NaCl, 2 mM CaCl₂, 2 mM MgCl₂, 1% OG, and fractions 21 to 30 were eluted with 5 mM EDTA in 20 mM Tris-HCl, pH 7.5, 50 mM NaCl, 1% OG. (B) Purified tonsillar CD34 was separated in L-selectin affinity chromatography and fractions were analyzed by dot blot analysis using anti-CD34 mAb 581 (numbers in figure refer to fraction numbers). Note that fractions 1 to 10 were collected with 20 mM Tris-HCl, pH 7.5, 50 mM NaCl, 2 mM CaCl₂, 2 mM MgCl₂, 1% OG, and fractions 11 to 20 were eluted with 5 mM EDTA in 20 mM Tris-HCl, pH 7.5, 50 mM NaCl, 1% OG. (C-D) Western blotting analysis of fractions from L-selectin affinity chromatography of CD34 (numbers refer to the same fraction numbers as in panel B). Immunostaining was performed using anti-CD34 mAb QBend10 (C) and MECA-79 mAb (D).