Highly reproducible human brain organoids recapitulate cerebral cortex cellular diversity.

Abstract Human brain organoids hold an unprecedented opportunity to observe, perturb, and study the early stages of human cortical development. Several protocols to generate brain organoids have been described in recent years [1, 2] . However, incomplete characterization and lack of organoid-to-organoid reproducibility has limited their application as an experimental model [3] . Here we describe a detailed protocol for the generation of human dorsal forebrain organoids that show highly reproducible generation of the rich diversity of cell types present in the developing human cerebral cortex. This protocol is a modification of a previous method described by Kadoshima et al . [4] . We also include a detailed description of the protocol used to dissociate organoids into single cells for single-cell RNA-sequencing.