In recent years, adoptive T cell-based immunotherapies have been developed to treat a wide range of hematologic malignancies, including relapsed or refractory non-Hodgkin lymphoma, B-cell leukemia, and multiple myeloma. Most of the commercially approved adoptive T cell therapies are composed of chimeric antigen receptor (CAR)-based T cells, which are a patient's own T cells engineered for recognition of a specific surface antigen, such as CD19 or CD20. Unselected peripheral blood mononuclear cells (PBMCs) have recently been used in several manufacturing protocols, but the vast majority of protocols still use CD4/CD8-selected T cells. The first step in manufacture of these CAR-T products involves simultaneous selection/purification of CD4