The CD4+ T Cell Isolation Kit has been developed for the isolation of untouched CD4+ T helper cells from human peripheral blood mononuclear cells (PBMCs). Non-CD4+ cells, i.e., CD8+ T cells, monocytes, neutrophils, eosinophils, B cells, dendritic cells, NK cells, granulocytes, γ/δ T cells, or erythroid cells are labeled by using a cocktail of biotin-conjugated antibodies. The cocktail contains antibodies against CD8, CD14, CD15, CD16, CD19, CD36, CD56, CD123, TCRγ/δ, and CD235a (Glycophorin A). Subsequently, non-target cells are magnetically labelled with the CD4+ T Cell MicroBead Cocktail. Isolation of highly pure T cells is achieved by depletion of magnetically labeled cells.