PneumaCult Alveolar Expansion Medium

From STEMCELL Technologies, PneumaCult™ Alveolar Organoid Expansion (AvOE) Medium is a serum-free culture system designed for the expansion of human alveolar epithelial type II (ATII) cells as organoids. It is part of a two-stage workflow in which primary isolated or cryopreserved human ATII single cells are first seeded in AvOE Seeding Medium, then transitioned to AvOE Medium on day 2–3 after a full-media change to obtain mature ATII organoids [S2, S3]. The medium supports long-term passaging and has been shown to enable over 10,000-fold expansion across multiple passages [S2, S3]. In reported culture data, organoid forming efficiency reached 27.5% when 160 cells were seeded per dome, yielding 44 organoids [S2].

Organoids cultured in AvOE Medium retain ATII phenotypic characteristics, including self-renewal capacity and expression of the ATII markers HT2-280 and pro-surfactant protein C (pro-SPC) [S2, S3]. They also retain lineage potential to differentiate into alveolar type I (ATI) cells when subsequently cultured in PneumaCult™ Alveolar Organoid Differentiation (AvOD) Medium for 10 additional days [S2]. Differentiated organoids express ATI markers including RAGE, GPRC5a, and HT1-56 [S2]. Both expansion- and differentiation-stage organoids express the SARS-CoV-2 entry-associated proteins TMPRSS2 and ACE2 [S2]. Single-cell suspensions of cultured organoids can be cryopreserved at any passage, with expansion potential retained after thawing [S2, S3].

The medium also supports downstream air-liquid-interface (ALI) workflows. Alveolar monolayers generated from expansion-phase ATII organoids can be seeded onto extracellular matrix-coated cell culture inserts and, once confluent at approximately 3–4 days post-seeding, airlifted to enable apical surface access [S1]. The product is intended for research use only [S3]. A California Proposition 65 warning applies because the product can expose users to progesterone, which is known to the State of California to cause cancer [S2].