Abstract: Objective To prepare polyclonal antibodies against human PIWIL, identify their property and investigate the tissue distribution of PIWIL. Methods PIWIL polypeptide was synthesized by chemical method, and conjugated to Keyhole limpet hemocyanin (KLH) as immunogen. Then PIWIL-KLH conjugations were injected into rabbits subcutaneously to produce polyclonal antibodies. The specificity and sensitivity of antibodies were identified by ELISA and Western blot after purification using affinity chromatography. PIWIL were then immune stained on the tissue chip to study their distribution. Results Rabbit antibodies against PIWIL were prepared after injection of PIWIL-KLH conjugation. These antibodies were confirmed to specially recognize PIWIL peptides. Expression of PIWIL was found in the cytoplasm of epithelia cells of varied normal tissue and tumor tissue . Conclusions The successful preparation of the polyclonal antibody against PIWIL will provide efficient reagent for further study of its role in the pathway of miRNA and RNA interference and in the pathogenesis of human disease.

Key words: Argonaute protein, Polyclonal antibody, Tissue chip