(0.1% v/v), B27 without vitamin A supplement (0.1% v/v), Insulin solution (0.1% v/v; Sigma), 2-Mercaptoethanol (0.1mM), Glutamax (1X v/v), MEM-NEAA (1X), and Penicillin/Streptomycin (0.1% v/v). After five days of being exposed to differentiation media containing B27 without vitamin A, the differentiation media was replaced by a formulation that is identical except for the replacement of B27 without vitamin A to B27 with vitamin A; at this time point, the brain organoids are also transferred to a 125-ml spinning flask bioreactor (Corning) siliconized with Sigmacote (Sigma), where they were fed differentiation media with vitamin A weekly for 8 weeks. After 12 weeks, Borgs were utilized for iMGL co-culture studies.
