Human peripheral blood monocyte-derived immature dendritic cells are derived from negatively selected monocytes. Non-monocytes are labeled and depleted from the peripheral blood mononuclear cell population using immunomagnetic particles leaving purified, untouched monocytes. Untouched monocytes are cultured for 4-5 days in culture medium containing 10% FBS plus GM-CSF and IL-4. After culture, cells are checked for the expression of CD11c, HLA-DR, and CD83 and the lack of CD14 expression by flow cytometry.