Figure 3.

IgE-binding capacity of nitrocellulose-dotted, baculovirus-expressed α-chain constructs. Sf9 cell supernatants containing recombinant α1-2 (a) or α2 (b) construct were dotted on nitrocellulose. Filter-bound proteins were incubated with serum from an atopic patient containing high IgE levels (lanes 1, 4, and 5), with chimeric monoclonal IgE (2), and with a human IgE–containing myeloma supernatant (3), and were detected with ¹²⁵I-labeled anti-human IgE RAST antibodies (1-3), a ¹²⁵I-labeled mouse monoclonal anti-human IgE antibody 12 (4), and, for control purposes, a ¹²⁵I-labeled human α chain (5).