In this protocol, lymphocytes are placed in the top chamber of a transmigration system, separated from the bottom chamber by a porous membrane. Chemokine is added to the bottom chamber, which induces active migration along a chemokine gradient. After 48 h, lymphocytes are counted in both chambers to quantitate transmigration.
Warren, K. J., Wyatt, T. A. Assessment of Lymphocyte Migration in an Ex Vivo Transmigration System. J. Vis. Exp. (151), e60060, doi:10.3791/60060 (2019).