PREPARATION OF MONOCLONAL-ANTIBODIES SPECIFIC FOR THE SUBCLASSES OF CANINE IGG

Canine IgG is composed of four subclasses, which are defined as IgG(1) , IgG(2), IgG(3) and IgG(4) on the basis of data from fast protein liq uid chromatography, and their electrophoretic mobilities and relative concentrations in serum. This paper describes the preparation of mAbs specific for determinants on canine IgG(2), IgG(3) and IgG(4). The mAb specific for IgG(2) resulted from a conventional immunisation protoco l. The mAb specific for IgG(3) was a result of immunisation with IgG(3 ) combined with the suppression of the immune response to IgG(1) by pa ssively administered anti-IgG(1) antibody. The mAb specific for IgG(4) resulted from immunisation with Fab or Fc fragments which were obtain ed by the cleavage of the IgG(4) molecule with papain. The specificity of each mAb was established by using an enzyme-linked immunosorbent a ssay which showed that all three specific clones recognised a determin ant in the Fd region of the canine immunoglobulin molecule.