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

Description

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. Applications Reported: This TRA-1-81 antibody has been reported for use in flow cytometric analysis, immunoprecipitation, immunoblotting, and immunofluorescence. Applications Tested: This TRA-1-81 antibody has been tested by flow cytometric analysis of the human embryonic carcinoma (EC) line 2102Ep. This can be used at less than or equal to 0.5 μg per test. A test is defined as the amount (μg) of antibody that will stain a cell sample in a final volume of 100 μL. Cell number should be determined empirically but can range from 10^5 to 10^8 cells/test.

This antibody has also been tested by immunoblotting of 2102Ep cell extracts, yielding a band of approximately 200-250 kDa (reducing and non-reducing conditions). This antibody has been tested by immunofluorescent staining of formaldehyde fixed and permeabilized cells and can be used at less than or equal to 5μg/mL. It is recommended that the antibody be carefully titrated for optimal performance in the assay of interest. Purity: Greater than 90%, as determined by SDS-PAGE. Aggregation: Less than 10%, as determined by HPLC. Filtration: 0.2 μm post-manufacturing filtered. 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.