CD4 is a 55 kDa glycoprotein that is a co-receptor for T cell receptor in T lymphocytes. CD4+ cells are essential for achieving effective immune response by associating with class II MHC molecules. 25%-65% human lymphocytes are CD4+. Human CD4 Isolation Kit is designed to isolate untouched CD4+ T helper lymphocytes. It contains a biotin labeled antibody cocktail and streptavidin conjugated magnetic beads. Through incubation of samples with biotin labeled antibody cocktail followed by incubation of streptavidin beads, the magnetically labeled non CD4+ cells are retained in the tube by magnetic separator. The untouched CD4+ T helper cells are collected in supernatant. Any downstream application can be performed on CD4+ cells after separation, such as Flow Cytometry and in-vitro culture and expansion.