Fig. 3

EpiPro^Plus medium enables long-term and large-scale expansion of purified breast epithelial progenitors. a Top panels: representative photomicrographs of bipotent progenitor-enriched subset of HBECs grown in 2D adherent cultures using EpiPro^Plus medium over five passages. Middle panels: representative FACS plots depicting CD49f and EpCAM expression in ex vivo expanded bipotent progenitor (CD49^brightEpCAM^low)-enriched fraction. Lower panels: representative photomicrographs of ex vivo expanded bipotent progenitors grown as organoids. b Top panels: representative photomicrographs of luminal progenitors (CD49^lowEpCAM^bright) grown in 2D adherent cultures using EpiPro^Plus media over five passages. Middle panels: representative FACS plots depicting CD49f and EpCAM expression in ex vivo expanded luminal progenitor (CD49^lowEpCAM^bright). Lower panels: representative photomicrographs of 3D organoids grown from ex vivo expanded luminal progenitors. Total cell number and CFC yield per passage calculated and plotted for (c) bipotent and (d) luminal progenitors for each individual sample. Bars represent 400 μm. Bipotent and luminal progenitors were obtained from three separate mammoplasty samples. A, B gated cell populations, CFC colony forming cell, P passage