WET AUTOCLAVE PRETREATMENT FOR IMMUNOHISTOCHEMICAL DEMONSTRATION OF ESTROGEN-RECEPTORS IN ROUTINELY PROCESSED BREAST-TISSUE

The immunohistochemical demonstration of oestrogen receptor (OR) was p erformed on 32 randomly selected and routinely processed breast carcin omas after wet autoclave pretreat ment of sections. The autoclave meth od was compared to the OR status found on frozen sections as well as t o alternative pretreatment methods such as enzymatic predigestion and microwave irradiation. Using four different monoclonal antibody clones (H222, LH1, CC4-5, 1D5.26), the OR status was evaluated for each of t he various pretreatment methods applied. All cases with a high OR cont ent on frozen sections (n=11) also showed a high OR status on wet auto clave-pretreated paraffin tissues using antibody clones 1D5.26 and CC4 -5; in cases with low OR content on frozen sections, no false-negative cases were recorded using only the antibody 1D5.26 neither after wet autoclave nor microwave pretreatment. In addition, with this antibody, OR was detectable after autoclave pretreatment in two cases which wer e considered to be OR-negative even on frozen sections. When the prima ry antibody was omitted, no false-positive cases were observed after w et autoclave pretreatment. Thus, in our hands, wet autoclave pretreatm ent, in combination with the antibody 1D5.26, offers a highly sensitiv e method for the immunohistochemical demonstration of OR in routinely formalin-fixed, paraffin-embedded sections of breast carcinomas.