At day 14, cerebral organoids (controls or PD173074 treated) were treated with 100 µM BrdU for 2 h (pulse phase), washed with DMEM-F12 three times and then incubated with media (control or PD173074) for an additional 4 days (chase phase). At day 18, organoids were harvested and double immunostained with rat anti-BrdU and mouse anti-Pan-Neu antibodies, as described in the next section.
