Flow cytometric analysis and quantification of MPs. (A) Determination of forward (FSC) and side-scatter (SSC) characteristics of light by 1.0-μm latex beads in buffer to establish the R-1 or MP gate. The R-2 or bead gate includes 7.2-μm latex beads used for enumerating MPs. (B) Detection of phosphatidylserine (PS)-positive MPs in platelet-free plasma (PFP) by annexin V-Cy5 labeling on the y-axis in relation to SSC on the x-axis. (C) Representative sample of MPs in PFP from a sickle sample triple labeled for annexin V (not shown), anti-TF-FITC on the x-axis, and anti-VE cadherin-PE on the y-axis.