Antigenic specificity of the mAbs.

Immunoprecipitation from surface-biotinylated resting platelets (A, C). NP-40 lysates were incubated with nonimmune rat IgG1 (control) or the indicated mAbs, followed by protein G-Sepharose. Proteins were separated on a 9%-15% gradient SDS-PAGE gel under nonreducing conditions, transferred onto a PVDF membrane and detected by streptavidin-HRP and ECL. (B) Western blot analysis of immunoprecipitated GPIIbIIIa with EDL1-3. Unlabeled platelet proteins were immunoprecipitated with nonimmune rat IgG1 (control) or MWReg30 (IIbIIIa), followed by SDS-PAGE and immunoblotting with FITC-labeled EDL1-3. Bound antibody was detected by HRP-labeled rabbit anti-FITC.