Protocol for optimizing culture conditions for ex vivo activation during CRISPR-Cas9 gene editing in human hematopoietic stem and progenitor cells.

Long-range correction strategies require ex vivo activation of hematopoietic stem and progenitor cells (HSPCs) to engage the homology-directed repair (HDR) mechanism, but prolonged culture causes harmful cellular responses, reducing the long-term functionality of gene-edited (GE) HSPCs. Here, we present a protocol for optimizing culture conditions for ex vivo activation during CRISPR-Cas9 gene editing in human HSPCs. We describe steps for HSPC thawing, ex vivo treatments, gene editing, and downstream in vitro and in vivo analyses to assess the functionality of GE-HSPCs. For complete details on the use and execution of this protocol, please refer to della Volpe et al.1.