Fig. 1

The principle and major steps of the FCIA assay. Platelet autoantibodies in ITP patient plasma were incubated with isolated normal platelets. The platelets were washed and lysed. Autoantibody-platelet antigen complexes were captured by microbeads coated with anti-platelet glycoprotein monoclonal antibodies (in different colors). The autoantibodies bound to microbeads were analyzed by flow cytometry using a FITC-conjugated goat anti-human IgG antibody. Levels of autoantibodies were determined based on values of mean fluorescence intensity (MFI) and standard corves with exogenous human IgG