S2644

Organoid sections were washed three times in 0.2% Triton-X in PBS (0.2%PBS/T) and then blocked in 10% normal goat serum diluted in 0.2%PBS/T (blocking solution) for 1 h at room temperature. Sections were incubated in primary antibodies diluted in blocking solution overnight at 4 °C and were subsequently washed three times with 0.2%PBS/T, followed by incubation with secondary antibodies and DAPI diluted in PBS/T at room temperature for 2 h. Finally, sections were washed three times (20 min per wash), and then mounted using Fluoromount mounting media (Southern Biotech). Primary antibodies used are as follows: mouse anti-Ki67 (1:250, BD Biosciences BDB550609), rabbit anti-SOX2 (1:500 Cell Signaling 3697S), rabbit anti-HOPX (1:500, Proteintech 11419-1-H), rat anti-CTIP2 (1:2000, Abcam ab18465), rabbit anti-TBR2 (1:1000, Abcam ab23345), mouse anti-SATB2 (1:1000 Abcam ab51502), mouse anti-NEUN (1:500, EMD Millipore MAB377), rabbit anti-NEUN (1:1000, EMD Milipore ABN78), rabbit anti-S100B (1:1000, Sigma S2644), chicken anti-MAP2 (1:5000, Abcam ab5392), rabbit anti-SYNAPTOPHYSIN (1:1000, Abcam ab14692), rabbit anti-HOMER (1:1000 Synaptic System 160003), and mouse anti-SYNAPSIN (1:500, Synaptic System 111011). Secondary antibodies conjugated with Alexa 488, 594, 647 (Invitrogen) and DAPI (1:1000, Sigma MBD0015) were used.