The route of transfer impacts cell migration into secondary lymphoid organs and the small intestine. Splenocytes of C57BL/6 mice were labeled with CFSE or TAMRA, and equal numbers of differentially labeled cells were injected intravenously and intraperitoneally into the same wild-type recipient. Five days after adoptive transfer, lymphoid organs and the small intestine were analyzed for the presence of transferred B cells (A-B) and T cells (C-D) by flow cytometry. Wild-type recipients were either untreated naive mice (A,C) or the recipients received drinking water containing 2.5% dextran sulfate sodium 4 days before adoptive transfer until 1 day after the transfer (B,D). Homing capacities are shown as ratios of intravenously transferred versus intraperitoneally transferred cells present in the respective compartments. ◇, the mean values observed in independent experiments performed with 4 to 5 recipients each; horizontal bars, the mean of all 3 experiments performed; SI, small intestine.