Cryosections of HUVEC showing adsorption control results. The sections were incubated with anti-TFPI diluted in medium containing rTFPI, and then with protein A-gold. (A) There is no label over the region of the Golgi complex (G) even though some nonspecific label (arrowheads) is seen over the nucleus. Bar = 0.5 μm. (B) Although the adsorption control did not completely abolish labeling (arrowheads), the amount of label is reduced and no label is observed over the many intracellular vacuoles (v) characteristic of these cells. Bar = 0.5 μm.