Lymphocyte homing assay consists of intravenous injection of fluorescent-labeled lymphocytes and measuring the number of labeled lymphocytes recovered in secondary lymphoid organs. One h (for short homing assay) to 24 h (for long term homing assay) after the injection of the labeled lymphocytes, lymph nodes, Peyer’s patches and other lymphoid organs are isolated and the number of fluorescent lymphocytes over total lymphocyte number is determined. This process can be inhibited by pre-injection of lectins that specifically bind to glycans that carry L-selectin ligands