Fig. 4. Comparison of neurogenesis and tissue morphology in brain organoids generated on chip and Petri dish. (A) Examination of TUJ1 and SOX2 markers in 33 day organoids (indicated by arrows) on chip and on Petri dish by immunohistochemical staining. (B) The apical marker CD133 expressed in organoids (indicated by arrows) on chip and on Petri dish at day 33 was verified by immunohistochemical staining, respectively. Scale bars = 50 μm.