CD4 T cells are also known as helper T cells because they act on other cells of the immune system to promote various aspects of the immune response including immunoglobulin isotype switching and affinity maturation of the antibody response macrophage activation and enhanced activity of natural killer cells and cytotoxic T cells Lonza CD4 T Cells are isolated from peripheral blood of healthy donors using negative immunomagnetic separation Cryopreserved CD4 T cells are guaranteed 90% pure for CD4 T cells as assessed by flow cytometry They are guaranteed to contain 10 million viable cells per vial HIV-1 hepatitis B and hepatitis C are not detected for all donors and/or cell lots A Certificate of Analysis is provided for each cell lot purchased Cells are available from multiple donors Please contact Customer Service for details on available inventory and donor demographic characteristics (age gender and ethnicity)