Detection of fractions of peripheral blood dendritic cells (DCs) by standardized 3-color flow cytometry. Peripheral blood samples were collected and the cells were stained with PerCP-conjugated anti-HLA-DR, PE-conjugated anti-CD11c or anti-IL3α (CD123), and FITC-conjugated lineage markers (lin1) containing anti-CD3, CD15, CD16, CD19, CD20, and CD56. After lysis of erythrocytes, the cells were analyzed by three-color flow cytometry. A: Events excluding debris and dead cells (R1); B: cells were gated on region R1, a dot blot of lineage marker (x axis) versus HLA-DR (y axis) was used to define the region of Lin-cells (R2); (C) pDC was defined as Lin1-, HLA-DR + , and CD123 + (R4); (D) mDC was defined as Lin1-, HLA-DR + , and CD11c + (R5). FITC: fluorescein isothiocyanate; FSC-H: forward scatter; PE: phycoerythrin; mDC: myeloid dendritic cell; pDC plasmacytoid dendritic cell.