Description: This H131 monoclonal antibody recognizes the human T cell receptor (TCR) Vβ13.1 allele. Composed of an α and β chain, TCR specificity is typically determined by Vα, Jα, Vβ, Dβ, and Jβ gene rearrangement. Vβ expression in humans has been examined in studies on the effects of superantigens, inflammation, autoimmune disease, and HIV infection. More recently, assessment of TCR Vβ expression has been used to phenotype T cell clonality in CD3+/TCRαβ+ large granular lymphocyte leukemias. A member of the Ig superfamily, this receptor is expressed on a subset of peripheral blood T cells.