Three healthy adults and three prostate cancer patients will be enrolled into the first cohort. Whole blood (150 ml) will be obtained by venipuncture. After processing of the blood to obtain peripheral blood mononuclear cells (PBMC), half of the PBMC will be treated with Cell Sense for 8-24 hours. Given the robustness of our data using 5 donors during dry runs, the investigators do not propose to compare labeled vs unlabeled cells as release criteria. However, the investigators will be collecting this data for information and research purposes. Three million (3 x 106) Cell Sense labeled autologous PBMC will be administered intradermally to the cohort 1 subjects. The three healthy adults and the 3 prostate cancer subjects will be tested concurrently.