Characterization of the MWReg30 MoAb. Binding characteristics of the MWReg30 MoAb were investigated (A) by flow cytometric analysis, which shows that all circulating mouse platelets were intensively stained with FITC-labeled MWReg30. The shaded area indicates platelets stained with an FITC-labeled control rat MoAb. (B) Mouse spleen sections were stained with MWReg30. (C) Immunoprecipitates with MWReg30 (lanes 1 and 3) or control rat IgG (lanes 2 and 4) obtained from lysates of surface-biotinylated platelets were analyzed by SDS-PAGE under nonreducing (lanes 1 and 2) and reducing conditions (lanes 3 and 4) by staining of the blotted proteins.