Effect of residual decrypting agents on fVIIa/TF activity and sensitivity to TFPI. The effect of residual decrypting agents on fVIIa/TF activity was assessed by using 5 μL rTF diluted 1:1000 as the source of TF and 5 × 10⁴ CHO cells. Activity measurements were performed as described in the presence of 10 nM fVIIa. (A) Rates of fVIIa/TF activity were determined in the presence (Buffer) or absence (No Cells) of CHO cells and also in the absence of added rTF (No rTF). Bars labeled MBCD and Octyl Glucoside indicate rates of fVIIa/TF activity in the presence of CHO cells incubated in the presence of indicated concentrations of MBCD or octyl glucoside. (B) CHO cells were incubated (10⁷/mL) in cell buffer, cell buffer containing 10 mM MBCD, or cell buffer containing 1% octyl glucoside, and aliquots containing 5 × 10⁴ cells were added to reactions containing rTF. Rates of fVIIa/TF were determined in the presence (+) or absence (-) of 5 nM TFPI or 5 μg anti-TFPI monoclonal antibody. In both panels, rates of fVIIa/TF activity are presented as a ratio to those obtained with buffer-treated CHO cells. Data presented are means ± SDs for at least 4 determinations. ^*P < .01 versus buffer-treated CHO cells.