From: Microparticles in kidney diseases: focus on kidney transplantation
Assay | Method | Advantages | Disadvantages |
---|---|---|---|
■Flow cytometry ■(fluorescence-activated cell sorting) ✓ MP counting | ■Utilization of fluorescence probes and light-scattering properties ■MPs in suspension | ■Available to most research facilities ■Rapid ■Multiple antigens may be analyzed in a single sample ■MPs analyzed on an individual basis ■The gold standard of human cell-derived MPs | ■Antibody binding might not occur attributable to the small fraction of surface antigens available ■Size limitations and not able to detect microvesicles with diameters less than 300–400 nm |
â– Immunoassays | â– ELISA-based MP capture assays by annexin V as a means of capturing phospholipids or antibodies to specific blood MP membrane antigens or antibodies to nonspecific antigens (detection antibody) | â– Available at most research institutions â– Alternative to flow cytometry approach â– Less costly than flow cytometry â– Not restricted by size | â– Analysis done in batches â– No size determination possible â– Quantifies based on a single antigen |
■Functional assays | ■Procoagulant or prothrombinase activity | ■Available at most research institutions ■Provides an indication of biological activity | ■The inability to quantitate the MPs ■Analysis done in batches, no size determination possible, measures procoagulant activity—not specific MP detection |
â– Atomic force microscopy | â– Scanning of MPs utilizing specialized microscope | â– MP size detection very accurate â– Allows for 3D structure of MP â– Quantitation of MPs | â– Allows for very accurate sizing of MPs â– Allows for 3D view of MP structure â– May be used for quantification |
â– Nanoparticle tracking | â– Light-scattering properties of MPs detected, video capture of MP motion | â– MP size detection, quantitation of MPs | â– Technology not readily available, long analysis times, costly |