Specificity and dose-dependent neutralization properties of mAb14C12. (A) mAb14C12 binds to microtitration plates coated with mAbBO2C11 but not to a human IgG4κ Ab of unrelated specificity or to an anti-FVIII C1 domain mAb (mAbLE2E9). (B) mAb14C12 inhibits the binding of mAbBO2C11 to plates coated with rFVIII. In panels A and B each point represents the mean of 2 determinations ± SD. (C) mAb14C12 or its Fab fragment neutralizes the FVIII inhibitory activity of mAbBO2C11 in a functional chromogenic assay as measured by single determination.