Immunohistochemistry Analysis (029429): Representative lot data. Paraffin-embedded human placenta tissue was prepared using heat-induced epitope retrieval in citrate buffer, pH 6.0. Immunostaining was performed using a 1:300 dilution of Bystin. Reactivity was detected using the IHC-Select® Detection Kit. Positive staining was observed in the syncytiotrophoblastic layer of the chorionic villi in human placenta.