The BD FACSAria Fusion is a high-speed sorter with a fixed-alignment, gel-coupled cuvette flow cell housed in a biosafety cabinet. This flexible cytometer provides superior performance in high-speed cell sorting and multicolor analysis, as well as index sorting. The lasers and nozzle, through which cells pass, are automatically aligned; their fixed positions ensure that results are reproducible. There are three nozzle sizes, designed to fit small, medium and large cells. The 4 laser, 16 color configuration allows users to easily sort up to four types of highly purified, sterile cell populations at a time. Our interest lies in accurately sorting immune cells such as macrophages and rare dendritic cells, and non-immune cells such as fibroblasts and endothelial cells. The index sorting feature allows us to review the complete cell surface phenotype of every cell sorted into a 96-well plate. These purified cell populations are crucial to building, and expanding, the Organ-on-a-Chip technology.