Ristocetin-induced VWF binding to GPIbα mutant cell lines.

Transfected cell lines were incubated with increasing concentrations of VWF (0-8 μg/mL) in the presence of ristocetin. Bound VWF was detected using an FITC-conjugated antihuman VWF antibody, followed by flow cytometric analysis. The data are expressed as a ratio of the mean fluorescence of VWF binding to that of AK3 binding and 2 points are presented: (A) 2 μg/mL VWF representing results obtained for the range of 0.5 to 4 μg/mL VWF and (B) 8 μg/mL VWF. The mean ratio ± SEM from 3 experiments is shown.