Antigen binding activity of recombinant antibodies and immunocytokines. Relative binding of Daudi cell-surface antigen was measured by FACS analysis following incubation with varying concentrations of recombinant proteins. Proteins included DI-Leu16-IL-2 (▪), DI-Leu16 antibody (□), chLeu16-IL-2 (▴), chLeu16 antibody (▵), and enzymatically deglycosylated DI-Leu16-IL-2 (○).