Abstract
One-way mixed lymphocyte reaction (MLR) is a classic tool to measure how T cells react to external stimuli. However, MLR is an in vitro reaction system, which shows different response intensity compared with in vivo trails sometimes due to the lack of cytokines, tissue matrix and other immune response associated factors. The following popliteal lymph node assay (PLNA) protocol is designed to test the T cells antigen-specific reaction in vivo by using ovalbumin (OVA) specific reacted transgenic mouse OT-1 and OT-2.