Fig. 4.

Binding characteristics of labeled multivalent scFvs. a Scatchard plot analysis of two sets of data from RIA experiments with scFv(1aa) using immobilised asialoglycophorin at two concentrations. From the slope of the trendline the functional affinity was calculated (Table 2). b Scatchard plot analysis of data from cell binding experiments with NM-D4 cells using scFv(0aa). The antibody affinity is calculated from the slope of the line, and the number of antibody binding sites per cell from the intercept with the x axis. c Lindmo plot of data from a series of cell binding experiments using serial dilutions of NM-D4 cells (in the range 1.0 × 10⁶ to 3.2 × 10⁷ cells) and the antibody scFv(1aa). Applying the law of mass action on the equation for the association constant, and correlating for the fraction of active antibody (r) yields an equation [17], from which an “r” value of 48% can be calculated