Abstract: After being mixed with Frund's adjuvant,horseradish peroxidase was used as antigen and injected into rat paw.Dynamic studies was carried out on:1.the retention time of antigen in local lymph nodes;2.the processing of antigen by macrophages;3.the effect on the synthesis of other unrelated immunoglubins after antigen stimulation.Four different histochemical and immunohistochemical methods were compared with light microscopy.Our results proved that the application of HRP,DAB and H₂O₂ as tracer substance and substrate for the studies on topics of cell biology and pathology makes it possible to observe the reaction products both in light microscope and electron microscope.It also permites to carry out comparative studies both at the bellular and ultrastractural levels.

Key words: horseradish peroxidase(HRP), antibody formation, antigen stimulation, synthesis of immunogloblin, histocytochemistry