Dendritic cells (DC) can either be generated from progenitors such as stem cells or CD14+ monocytes, or isolated directly from the blood. Blood-derived DC are present as at least two distinct populations-myeloid and plasmacytoid DC. Here we describe methods for the clinical-grade isolation of blood DC and DC precursors using the CliniMACS. We describe the isolation of ultra-pure monocytes in order to generate large numbers of monocyte-derived DC, and also new methods for the direct isolation of blood DC. Isolation of blood DC in large numbers means that natural DC with different properties can be investigated for their clinical function for the first time.