Mouse Monoclonal MIB1 Antibody

The MIB1 antibody is a monoclonal antibody widely used to detect the Ki-67 antigen, a nuclear protein expressed in proliferating cells during active phases of the cell cycle (G1. S, G2. and M phases) but absent in quiescent (G0) cells. The Ki-67 protein, encoded by the *MKI67* gene, is a large, highly charged molecule with multiple phosphorylation sites and conserved structural motifs, such as PPXY repeats, which mediate interactions with chromatin-associated proteins. Discovered in the 1980s, Ki-67 serves as a key biomarker for assessing cell proliferation rates in both research and clinical settings. The MIB1 clone, developed by immunizing mice with recombinant Ki-67 fragments, specifically recognizes a formalin-resistant epitope, making it suitable for immunohistochemical (IHC) staining in paraffin-embedded tissues. Clinically, MIB1 staining is pivotal in oncology for grading tumors, predicting prognosis, and evaluating therapeutic responses, as high Ki-67 indices often correlate with aggressive tumor behavior and poor outcomes. However, interpretation requires context, as proliferation rates vary across tissue types and malignancies. Despite limitations like interlaboratory variability in scoring, MIB1 remains a cornerstone tool in pathology, bridging cellular dynamics with disease management strategies.