Western blot for detection of antibodies to human F.IX in subjects in study.

Serum samples were collected at monthly intervals from all subjects and used in a 1:1000 dilution as the primary antibody in an immunoblot to detect antibodies to human F.IX. Shown here are samples from each subject, drawn at a series of time points ranging from 5 weeks to 44 weeks after vector injection. The positive control (+) is performed using serum from a patient with an inhibitor (24 BU) to F.IX and the negative control is serum from a healthy subject.