This monoclonal antibody is an IgG2b isotype switch 
  variant (Beun et al., 1993) of the well-known R73 IgG1 monoclonal antibody that is specific 
  for the rat aß-T cell receptor (Hünig et al. 1989).

  The R73-2b monoclonal antibody binds to an epitope of the constant region of the rat aß-T 
  cell receptor. It is able to activate rat T cells (Beun et al., 1993). The reactivity of R73-2b 
  monoclonal antibody is rat strain-independent. R73-coated culture flasks induce rat T cell 
  proliferation (Beun et al., 1993).

  R73-2b is useful in flow cytometry, but can also be used in other techniques, including 
  immunohistochemistry of fresh-frozen tissues. It can also be applied in assays that are based 
  on T cell activation. There is a bispecific antibody available (R73xCC52, ARA17) that consists 
  for one half of this antibody and the other half of an antibody directed against a rat tumor antigen
  of epithelial origin. This bispecific antibody is able to induce T cells to lyse the appropriate tumor 
  cells.

  Beun GD, Van De Velde CJ, Fleuren GJ (1993) T-cell retargeting using bispecific monoclonal 
  antibodies in a rat colon carcinoma model: III. Activation of resting T cells and tumor neutralization 
  induced by bispecific antibodies. J Immunother 13: 223-231

  Hunig T, Wallny HJ, Hartley JK, Lawetzky A, Tiefenthaler G (1989) A monoclonal antibody to a 
  constant determinant of the rat T cell antigen receptor that induces T cell activation. Differential 
  reactivity with subsets of immature and mature T lymphocytes. J Exp Med 169: 73-86