Table 1.

Two processes for the isolation of either culture-derived microparticles or platelet-derived microparticles

Culture-derived microparticles	Platelet-derived microparticles
Megakaryocyte cultures	Megakaryocyte cultures
↓	↓
200 ×g, 15 min	200 ×g, 15 min
↓	↓
Spin supernatant 1200 ×g, 10 min	Spin supernatant 1200 ×g, 10 min
↓	↓
Spin supernatant 3000 ×g, 15 min	Resususpend platelet pellet in activation bu3er
↓	↓
Spin supernatant 10 000 ×g, 60 min	Activate for 30 min, 37 °C
↓	↓
Resuspend microparticle pellet	Spin 3000 ×g 15 min
↓	↓
Add to ‘target’cells	Spin supernatant 21 000 ×g, 30 min
	↓
	Resuspend microparticle pellet
	↓
	Add to ‘target’cells
Megakaryocyte and platelet origin	Platelet origin
Higher yield per culture volume	Low yield per culture volume

In order to generate enough microparticles for subsequent experiments, a minimum of 100 mL of starting megakaryocyte cultures was grown at confluency (4 × 10⁵ cells mL⁻¹) for at least 3 days before beginning isolations by centrifugation. When supernatants were transferred to new tubes, at least 1 mL of medium was left with the undisturbed pellet to ensure that pelleted cells were not transferred. All steps were performed at room temperature, except where otherwise noted.