The TRA-1-81 monoclonal antibody reacts with a pluripotent-stem-cell-specific antigen expressed upon the surface of human embryonic stem (ES) cells, embyronal carcinoma (EC) cells, and embryonic germ (EG) cells. The expression of TRA-1-81 antigen is stage-specific; as human EC and ES cells undergo differentiation, expression of TRA-1-81 antigen is lost, making it a widely used marker to characterize human ES cells and to monitor their differentiation. TRA-1-81 antibody recognizes a carbohydrate epitope expressed on podocalyxin, a sialoglycoprotein structurally related to CD34. Podocalyxin is a transmembrane glycoprotein which has been implicated in the development of aggressiveness in a variety of cancers, including breast and prostate cancer.
ICC analysis of TRA-1-81 on H1 human ES cells at 20x magnification. Cells were stained with TRA-1-81 Antibody (Purified) at a 1:100 dilution followed by a secondary DyLight 488 conjugated antibody (green). DAPI staining was performed to visualize nuclei (blue).
Immunocytochemistry analysis of TRA-1-81 on H1 human ES cells. Cells were stained with TRA-1-81 Antibody (Purified) at a 1:100 dilution followed by a secondary Cy™ 3 conjugated antibody (red). DAPI staining was performed to visualize nuclei (blue).
Flow cytometry of TRA-1-81 on H1 human ES cells. Purple histogram represents TRA-1-81 Antibody (Purified) and open histogram represents isotype control at same concentration.
