IC detection within the MP gate by FC. (A) Density plots showing PBS background and isolated MP preparation. Arrows indicate 1 μm calibration bead. R1 indicates the MP gate. (B) AX-PE- and CD42a-FITC-stained events within the MP gate from normal blood plasma. Two distinct populations can be recognized: an AX⁺/CD42a⁺ (platelet MPs) and an AX⁺/CD42a⁻ (nonplatelet MPs) one. (C) Scatter plots of LF-anti-LF (1:10 ratio) IC and OVA-anti-OVA (1:1 ratio) IC. Arrow indicates 1 μm calibration bead. R1 indicates the MP gate. (D) Fluorescence intensity plot of mouse IgM-antimouse IgM-FITC (1:1) IC. Events are shown within the R1 gate. (E) The histograms show the effect of different antigen/antibody ratios on LF-anti-LF, OVA-anti-OVA, and IgM-antimouse IgM-FITC IC formation. The y-axes represent total event counts within the MP gate.