THE M1G8 MONOCLONAL-ANTIBODY - A COMPARISON BETWEEN PARAFFIN-EMBEDDEDAND FROZEN-SECTIONS FROM BREAST-CANCER

Till now the immunohistochemical studies on the procathepsin D express ion in breast cancer have been performed using polyclonal antibodies o n paraffin-embedded sections because the monoclonal ones were consider ed effective only on frozen sections. In this study we compared the MA b M1G8 reactivity, which recognizes the 52 Kd procathepsin D, on a ser ies of frozen and paraffin-embedded sections of the same specimen from 22 breast cancers, using the immunohistochemical method. This methodo logical choice was due to the necessity to perform further studies wit h monoclonal antibodies using archival material to clarify the procath epsin D prognostic role. MAb M1G8 was clearly positive with a 100% con cordance rate both in frozen and paraffin sections of the same specime n.