CD90 (Thy-1) Antibody Staining Protocol for Immunohistochemistry

Description: The OX-7 antibody reacts with the rat Thy-1 antigen (CD90)1 expressed by hematopoietic stem cells, early myeloid and erythroid cells,4 immature B lymphocytes in the bone marrow and peripheral lymphoid organs, thymocytes, recent thymic emigrants (a subset of CD45RC- peripheral T lymphocytes), neurons, glomerular mesangial cells, endothelium at inflammatory sites, mast cells, and dendritic cells. Rat dendritic epidermal T cells (DEC) are Thy-1-negative, unlike those of the mouse. CD90 is a GPI-anchored membrane glycoprotein of the Ig superfamily which is involved in signal transduction. OX-7 antibody cross-reacts with the mouse Thy-1.1 alloantigen of the AKR/J and PL strains, but not Thy-1.2 found on most mouse strains. In the mouse, CD90 is found on thymocytes, most peripheral T lymphocytes, some intraepithelial T lymphocytes (IEL, DEC), hematopoietic stem cells, and neurons, but not B lymphocytes. In addition, there is evidence that CD90 mediates adhesion of mouse thymocytes to mouse thymic stroma. The OX-7 antibody has also been reported to cross-react with rabbit and guinea pig thymus, brain, and intestine.