Figure 2.

Frequency of tethering in shear flow of neutrophils to P-selectin at three different viscosities. Transient tether frequency on P-selectin diluted 1:40,000 was determined as the number of tethering events per second divided by the number of cells in the field of view near the wall of substrate in Hanks' balanced salt solution/Hepes buffer containing 2 mM Ca²⁺ and 0, 3, and 6% of Ficoll. The same data are plotted vs. wall shear stress (A) and shear rate (B).