TRA-1-81 (Podocalyxin) Monoclonal Antibody (TRA-1-81), eBioscience™, Invitrogen™

Description

The TRA-1-81 antibody recognizes a protein expressed on undifferentiated human embryonic stem cells (ES), embryonic carcinoma cells (EC), and embryonic germ cells (EG). Like other stem cell specific markers, the epitope recognized by the TRA-1-81 antibody is lost upon cell differentiation. The TRA-1-81 epitope is resistant to neuraminidase digestion, unlike the epitope recognized by the related TRA-1-60 antibody. The TRA-1-81 antibody is known to specifically recognize a carbohydrate epitope on a keratan sulfated glycoprotein recently identified as podocalyxin, a member of the CD34-related family of sialomucins. Podocalyxin is a transmembrane glycoprotein originally identified on epithelial glomerular cells known as podocytes, and the protein has also been implicated in the development of aggressiveness in a variety of cancers, including breast and prostate cancer.

TRA-1-81 is a cell surface antigen expressed along with SSEA-3, SSEA-4 and TRA-1-60 in human embryonic stem cells, embryonal carcinoma cells and induced pluripotent stem cells (iPS). These surface markers are down-regulated during the differentiation process. In contrast, SSEA-1 is absent in undifferentiated human stem cells but is present on the cell surface after retinoic acid mediated differentiation.