Splenocyte-derived apoptotic microvesicles from MRL/lpr mice contain more (modified) chromatin compared to BALB/c splenocyte-derived microvesicles. (A) Microvesicles from apoptotic splenocytes of 8- to 10-week-old MRL/lpr mice (n = 12) were stained for lupus-mouse derived mAbs #34, KM-2, BT164 and LG11-2, and compared to splenocytes from BALB/c (n = 11) and C57Bl/6 mice (n = 7). *P <0.05. (B) Representative example of a forward scatter/side scatter (FSC/SSC) plot for BALB/c and MRL/lpr splenocyte-derived apoptotic microvesicles demonstrating comparable microvesicle-populations. (C) 4-NQO-induced apoptosis for BALB/c and MRL/lpr splenocytes after 16 hours was determined by flow cytometry using annexin V-fluorescein isothiocyanate (FITC) and propium iodide (PI). (D) The percentage of CD3- and CD19-positive apoptotic microvesicles for splenocytes of MRL/lpr and BALB/c mice 16 hours after induction of apoptosis was measured by flow cytometry.