The lung epithelium undergoes a complex series of endodermndashmesoderm-mediated signaling events to generate a complex arborized network of conducting airway (bronchi bronchioles) and gas-exchanging units (alveoli). Lung epithelium differentiation stages include anterior/posterior and dorsal/ventral patterning lung specification lung budding branching morphogenesis and maturation. The 3dGRO Lung Organoid Maturation Medium is a chemically defined/serum-free ready-to-use media used to differentiate lung bud organoids (LBOs) into mature lung organoids that structurally resemble the in vivo branching airway and early alveolar structures. Large numbers of mature lung organoids may be generated that express appropriate markers indicative of multiple cell types found in the mature lung and airways including SfTPB and SfTPC MUC5AC EpCAM Sox9 Nkx2.1 acetyl-a-tubulin and Vimentin. Additionally the mature lung organoids express ACE2 and TMPRSS2 for SARS-CoV2 viral research. The 3dGRO