Lrp5 in Mammary Stem Cells Figure 4. Lrp5 is Expressed by Cells that Co-Purify with Stem Cells by Flow Cytometry. A) Single cell preparations of virgin BALB/c MECs were stained with CD24, CD49f, CD45, and CD31, in addition to Lrp5 prior to FACS analysis. Gates were set to distinguish Lrp5 negative (red), low (blue), and high (green) expressing MECs. The CD24/CD49f profiles for each population were then overlaid. Arrow in Lrp5 high panel indicates previously uncharacterized region of CD24/CD49f profile. B) MECs were stained with von Willebrand factor (VWB), in addition to CD49f and CD24. Gates were drawn to indicate VWB positive and negative populations and the CD24/CD49f profiles were plotted for each respective population. Arrow indicates VWB+ cell population that co-localizes with a fraction of Lrp5 high MECs shown in A. C) Lrp5+ and Lrp5- MEC fractions were isolated by FACS and stained for Vimentin and VWB expression. doi:10.1371/journal.pone.0006594.g004 PLoS ONE | www.plosone.org 6 August 2009 | Volume 4 | Issue 8 | e6594