Differentiation of iPSCs into NPCs

The use of human iPSCs was approved by the Institutional Review Board (IRB) of Yonsei University (Permit Number: 7001988-201802-BR-119-01E). We cultured iPSC on Matrigel (354277, BD Biosciences (San Jose, CA, United States)) with Essential 8 medium (A1517001, Invitrogen (Carlsbad, CA, United States)) coating [20 (link),21 (link),22 (link)]. For the differentiation of iPSC into NPC, an embryoid body (EB) was generated through the culturing of human iPSCs for 5–6 days on non-adherent petri dishes in Essential 8 (Invitrogen) with additional supplement 5 μM dorsomorphin (DM) (P5499, Sigma-Aldrich (St. Louis, MO, United States)) and 5 μM SB431542 (Sigma-Aldrich)). Then we attached EBs in the new culture dish coated with Matrigel (BD Biosciences) with neural induction medium comprised of DMEM/F12 medium (11320033, Invitrogen), 1× N2 supplement (17502048, Invitrogen), 1× nonessential amino acids (11140050, Invitrogen) for 6 days. When neural rosette formation appeared in the center of the EBs, NPCs were collected for analysis [23 (link),24 (link),25 (link)].