Figure 3

Affinity determination of RAb^DMvIII by Saturation ELISA. Calibration curve of the binding of RAb^DMvIII and RAb^vIII recombinant antibodies to coated EGFRvIII in the ELISA. A) The concentration range for RAb^DMvIII and RAb^vIII was 20 to 0.02 ug/ml (x axis) and the absorbance was read at 450 nm (Y axis). The assay was analyzed twice. B) Saturation ELISA shows the Scatchard plot of the binding of RAb^DMvIII to EGFRvIII. The resulting data is plotted as ratio of α/c (y axis) as function of alpha (x axis) where α is the fraction of bound antibody sites and c is the concentration of free antigen. The slope is -K which is the affinity constant of antibody and that is 1.7 × 10⁷ liters/mole (M^-1).