Defined conditions for long-term expansion of murine and human alveolar epithelial stem cells in three-dimensional cultures

Alveolar type 2 cells (AT2s) serve as stem cells of the alveoli and restore cell numbers after injury. Here, we describe a detailed protocol for the isolation, purification, and culture of murine and human AT2s. We have developed chemically defined and stroma-free culture conditions that enable expansion and maintenance of AT2s. The culture conditions are scalable and compatible with high-throughput chemical and genetic screenings and can potentially be used to generate large AT2 numbers for cell-based therapies. For complete details on the use and execution of this protocol, please refer to Katsura et al. (2020).