Are silica microspheres superior to polystyrene for microvesicle analysis by flow cytometry?
Use of 1.0-μm polystyrene microspheres to define the upper MV gate produced a median platelet contamination of 16.53% (8.24, 20.98) of the MV population; whereas, use of 1.0-μm silica microspheres excluded platelet events completely. Calibration with silica microspheres resulted in significantly better estimation of MV diameter than calibration with polystyrene microspheres. We conclude that silica microspheres are superior to polystyrene microspheres as standards to define MV populations without platelet contamination and to determine MV sizes by flow cytometry for a given cytometer.
The therapeutic temporal window of immunotherapy post-RT suggests that highly aggressive, immuno-suppressive tumors might be most sensitive to immunotherapy in a fairly narrow time window; these results should help to guide future development of clinical combinatorial strategies.