For Research Use Only in the United States and Canada. U-CyTech Products are Available Worldwide. Human CD3/CD28 positive control in ELISPOT. Specificity: To be used as a polyclonal T cell activator in the human cytokine ELISPOT analyses. The vial contains two antibodies specific for human CD3 and CD28. A variety of different cytokines are elicited by this antibody combination including IFN-gamma, IL-2, IL-4, IL-5, IL-10 and IL-13.