Fig 1: Flow cytometry analysis of the identity of post-Passage 3 culturesPassage 3 cryopreserved primary fibroblasts were thawed and analyzed 24 h later by flow cytometry. Data was analyzed with Flowlogic v8.(A) Gating strategy applied to a representative culture of primary fibroblasts (derived from a young 4 months-old male). Debris is first gated out from the FSC-A vs. SSC-A plot of the entire population. Single cells are then gated based on the FSC-A vs. FSC-H plot. From this singlet population, CD45- cells are obtained by gating on the CD45 vs FSC-A plot. Finally, we use this CD45- population to gate for CD90.2+ and CD140a+ cells.(B) Same gating strategy as in (A) applied to a population of peritoneal lavage cells, which should contain a large fraction of immune (CD45+) cells.(C) Fibroblast cultures from three 4 months-old males and females were analyzed by flow cytometry, and a beeswarm plot was generated for the percentage of cells staining for combinations of immune (CD45) and fibroblast (CD90.2 and CD140a) markers.(D) The same plot as in (C) but for a population of peritoneal lavage cells as a CD45+ control population.