Background of the antigen
Beta 2 Microglobulin non-covalently associates with the 44 kDa alpha chain to form the HLA Class I antigen complex. Human beta 2 Microglobulin associated with HLA Class I antigens are expressed on many types of cells including lymphocytes, thymocytes, monocytes, granulocytes, platelets, endothelial cells, and epithelial cells. It is absent on erythrocytes.