LEFT, MIDDDLE: Normal human peripheral blood cells were unstimulated (left) or stimulated overnight with Human IFN alpha 2a Recombinant Protein (Product # 111011) (middle). Cells were then stained intracellularly, using the Foxp3/Transcription Factor Staining Buffer Set (Product # 00-5523) and protocol, with CD303a Monoclonal Antibody, PE-Cyanine7 (Product # 25-9818) and IRF7 Monoclonal Antibody, Alexa Fluor 647. Viable cells in the pDC gate, as determined by Fixable Viability Dye eFluor 506 (Product # 65-0866), were used for analysis. RIGHT: CD303a+ pDC cells stained with Rat IgG2a kappa Isotype Control, Alexa Fluor 647 (Product # 51-4321) (blue histogram) or IRF7 Monoclonal Antibody, Alexa Fluor 647 (Product # 51-5375) on unstimulated (orange histogram) or Human IFN alpha 2a Recombinant Protein (Product # 111011)-stimulated human peripheral blood cells (purple histogram).