anti-Ubiquitin antibody: Ubiquitin (Ub) plays a very important role in regulated non- lysosomal ATP dependent protein degradation. The protein to be degraded is conjugated to Ub and the ubiquinated protein is then selectively degraded by a 26S complex, multicatalytic cytosolic and nuclear protease termed proteasome. The Ub- proteasome proteolytic pathway, which is a complex process, is implicated to be of great importance for regulating numerous cellular processes. Immunohistochemistry (IHC) is a complex technique in which immunological and histological detection methods are combined. In general, the manipulation and processing of tissues before immunostaining, especially different types of tissue fixation and embedding, as well as the nature of the tissues themselves may cause inconsistent results (Nadji and Morales, 1983). Endogenous pseudoperoxidase and peroxidase activity or endogenous biotin and alkaline phosphatase activity can cause non-specific staining results depending on the detection system used. Tissues that contain Hepatitis B surface antigen (HBsAg) can produce false positives when using HRP detection systems (Omata et al, 1980). Insufficient contrast staining and/or improper mounting of the sample may influence the interpretation of results.