HIV-1 infection of hES and FL DCs: To determine virus susceptibility, FL and hES DCs were infected with a replication competent X4-tropic HIV-GFP reporter virus strain at an m.o.i. of 0.2. At 6 days post infection, cells were visualized by fluorescence microscopy to determine GFP expression in productively infected cells at the single cell level. Phase contrast and fluorescence images are shown for the respective cell types (A). Infected culture supernatants were assayed for viral p24 antigen by ELISA at different days post-infection (B). Data is representative of duplicate experiments.