We describe a method of monitoring the state of a cell, tissue, organ or organism. The method comprises establishing, for a sample of micro-particles from the cell, tissue, organ or organism, a ratio. The ratio is of a selected polypeptide in microparticles which comprise GM1 gangliosides, preferably which bind to Cholera Toxin B (CTB) (“GM1 ganglioside microparticle polypeptide”) to the selected polypeptide in microparticles which comprise exposed phosphotidylserine, preferably which bind to Annexin V (“Annexin V microparticle polypeptide”). The GM1 ganglioside microparticle polypeptide to Annexin V microparticle polypeptide ratio so established may be indicative of the state of the cell, tissue, organ or organism.