Titration of ATD protein in a capture ELISA. A titration of TEV-mobilized ATD was tested for binding to plate-adherent 5F5 mAb. ATD was biotinylated and tested from 65 pg/ml to 5 μg/ml, in triplicate samples, and detected with SA-HRP. The relative luminescence signal was measured. Calculated R2 = 0.99955. RLV, relative luminescence value. Bars indicate the S.E.M.