NEW ANTISERUM AGAINST KI-67 ANTIGEN SUITABLE FOR DOUBLE IMMUNOSTAINING OF PARAFFIN WAX SECTIONS

Aims-To prepare a rabbit antiserum equivalent to MIB 1 to permit the s imultaneous assessment of cell proliferation and other markers of inte rest using double labelling studies. Methods-Rabbits were immunised wi th a synthetic peptide deduced from the cDNA sequence coding for the K i-67 antigen. Serum samples were tested for immunoreactivity using dif ferent immunobiochemical methods. Results-A polyclonal antiserum was d erived which detects the native as well as recombinant parts of the Ki -67 antigen in different test systems. Furthermore, the antiserum stai ns the Ki-67 antigen in routinely processed, paraffin wax embedded mat erial. Conclusions-After antigen unmasking by microwave treatment the antiserum described here represents a powerful tool for the determinat ion of growth fractions even in archival material. It is especially su itable for double staining experiments in combination with monoclonal antibodies.