Figure 2.
Competition between oligomers of IgE. (A) Protocols for stimulating cells and immunoprecipitating their receptors. RBL-2H3 cells (6.25 × 106/ml) were reacted with 0.3 μg/ml of rat IgE oligomer. After 10 min, 3 μg/ml of mouse IgE oligomer was added. As a control, 3 μg/ml monomeric mouse IgE was added instead. At t = 9 and 20 min, rat IgE was immunoprecipitated and the phosphotyrosines on the bound FcɛRI were analyzed. (B) Densitomeric quantitation of the blot for the experiment shown in A. The bars show the averages of two samples, and the ranges of the duplicates are shown.