Abstract: The purpose of this study is to investigate the feasibility of labeling skin of Inner Mongolia Cashmere Goats with 5-bromo-2-deoxyuridine(BrdU), and to optimize its immunohistochemical conditions. Different dosage of BrdU was injected intravenously into goats’neck. Skin samples were taken from the back of the goats, then fixed in 4% paraformaldehyde and embedded with paraffin. The samples were examined with immunohistochemical technology to estimate effects of influence factors on labeling results such as the BrdU injection dosage, the dilution of second antibody and streptavidin-peroxidase, the way of antigen pretreatment, and DNA denature temperature. Positive cells with red nuclear were observed in labeled goats. However, positive signals were not observed in the samples from unlabeled goats and those incubated with PBS instead of BrdU-antibodies from labeled goats. BrdU can be used for labeling on Inner Mongolia Cashmere Goats in vivo. The optimal immunohistochemical results were shown in the conditions that denaturing DNA in 2 mol/L HCl for 30 min at 37 ℃, and repairing antigens in trypsin for 30 min at 37 ℃ and the dilution of biotin-conjugated second antibody and streptavidin-peroxidase is 1∶100.t; immunohistochemistry; labeling

Key words: BrdU; Cashmere goat; immunohistochemistry; labeling