Ki-67 Monoclonal Antibody (20Raj1), eBioscience™, Invitrogen™

Description

Description: The monoclonal antibody 20Raj1 recognizes the human Ki-67 protein. Two isoforms of Ki-67 exist, a 345 and 395 kDa form that are expressed in dividing cells. Ki-67 is expressed in all cell types and is detectable during active phases of the cell cycle (G1, S, G2, and mitosis) but is absent from resting cells (G0). During interphase, Ki-67 expression is localized to the nucleus but redistributes to the chromosomes during mitosis and has specifically been found to associate with heterochromatin-bound proteins such as chromobox protein homolog 3 (CBX3). In studies of tumor cells, Ki-67 expression has been used as a marker for determining the fraction of proliferating cells within a given population of tumor cells. This monoclonal antibody 20Raj1 recognizes canine (dog) Ki-67. Applications Reported: This 20Raj1 antibody has been reported for use in immunocytochemistry and immunohistochemistry on formalin-fixed paraffin embedded tissues. Applications Tested: This 20Raj1 antibody has been tested by immunocytochemistry on paraformaldehyde fixed and permeabilized MCF7, MDCK, and MDA-MB-175 cell lines. This 20Raj1 antibody has been tested by immunohistochemistry on FFPE human skin using citrate buffer antigen retrieval. For immunocytochemistry and immunohistochemistry, this can be used at less than or equal to 0.5-1 μg/mL. It is recommended that the antibody be carefully titrated for optimal performance in the assay of interest.

Ki-67 is a nuclear protein that is expressed during various stages in the cell cycle, particularly during late G1, S, G2, and M phases. The protein has a forkhead associated domain (FHA) through which it associates with euchromatin at the perichromosomal layer, the centromeric heterochromatin, and the nucleolus. Ki-67 is shown to have a cell cycle dependent topographical distribution with perinucleolar expression at G1, expression in the nuclear matrix at G2, and expression on the chromosomes during M phase. Ki-67 is commonly used as a proliferation marker because it is not detected in G0 cells, but increases steadily from G1 through mitosis. Ki-67 antibodies are useful in establishing the cell growing fraction in neoplasms. In neoplastic tissues, the prognostic value is comparable to the tritiated thymidine-labelling index. The correlation between low Ki-67 index and histologically low-grade tumors is strong. Ki-67 is routinely used as a neuronal marker of cell cycling and proliferation.