Cell Type Characterizations from Day 14 and Day 84 Human Cortical Organoids. A) Experimental design showing critical steps for differentiation, collection timepoints, and assays. B) tSNE plot of detected cell types across all sites and time points. Abbreviations: NPC, G2: neural progenitor cells, G2-phase. IP, S: intermediate progenitor, S-phase. NPC, S: neural progenitor cell, S-phase. IP: non-dividing intermediate progenitor. oRG: outer radial glia. RG: radial glia. NSC: neuroepithelial stem cell. Neuron: unspecified neuron. Pan CN: pan-cortical neuron. ULN, a: Upper-layer cortical neuron, group a. ULN, b: Upper-layer cortical neuron, group b. LLN, a: Lower-layer cortical neuron, group a. LLN, b: Lower-layer cortical neuron group b. PN/CR: Pan neuron and Cajal–Retzius. MP/MZ: medial pallium and marginal zone. C) tSNE plots colored by differentiation day, inferred cell cycle phase, or gene expression of previously defined markers. D) Organoid cell type correlations to primary fetal telencephalic tissue (Bhaduri et al. 2020). Pearson’s correlation coefficients above 0.3 and surviving an FDR (BenjaminiHochberg) adjusted p value threshold of 0.05 are labeled.