Bright field images of embryonic lung epithelial 3D explants cultured for 3 days in matrix. (A-D) Explants cultured in the presence of day 20 milk, (E-H) day 60 milk, (I-L) day120 milk and (M-P) in the absence of milk. (Q-T) The effect of tammar milk on the morphology of embryonic lung epithelial explants. Epithelial membranes were visualised by staining with E-cadherin (green) and cell nuclei with Dapi (blue). (Q) Explants treated with day 20 milk showed a disorganized cell mass and no lumen. (R) Explants treated with day 60 milk show a large lumen surrounded by columnar epithelial cells. (S) Explants treated with day 120 milk show a small lumen lined with columnar epithelial cells. (T) Explants cultured in the absence of milk showed no defined lumen and a disorganized cell mass. (U-X) Cell proliferation of epithelial explants was observed by immunostaining with PCNA antibody (brown) and counterstained with haematoxylin (blue). (U) Explants treated with day 20 milk showed minimal cell proliferation in comparison to explants treated with day 60 milk (V), and almost all cells stained with PNAS. (W) Embryonic lung treated with day 120 milk showed a reduced number of cells stained with PCNA compared to explants cultured in day 60 milk. (X) In explants in control media there was no evidence of PCNA staining in the cells. (Q-X) Scale bar 100 μm, (A-P) Scale bar 200 μm.