MP analysis by flow cytometry and electron microscopy.

<p>Calibration of Navios cytometer using 0.1, 0.3, 0.5, and 0.9 μm beads (Biocytex). The cytometer is able to differentiate the 4 different populations of beads (A-B). We can delimit the gate in accordance with size to study MPs (0.3–0.9 μm) (C). Characteristic elongated shape of MPs repartition limited in a gate of 0.3–0.9 μm. (D). Labeling of platelet derived-MPs with CD41 and annexin-V revealed a double positive population for these markers (E). Example of 7-AAD/annexin V labeling to detect the presence of apoptotic bodies (AB). (F). Absence of contamination with AB. To monitor the presence of protein complexes (PC), lysis with 0.05% triton was used. After lysis, the positive signal disappeared (G). Scanning Electron Microscopy (SEM) shows the production of MPs by B-lymphocytes (white arrows) (H). Transmission electron microscopy (TEM) shows the structure of one MP with a characteristic lipid bilayer (white arrows) (I).