Significance of Wet Autoclave Pretreatment in Immunohistochemistry

Ágnes BÁNKFALVI1, József PIFFKÓ2, Dietmar ÖFNER3, Rita DREIER1, Werner BÖCKER1, Kurt Werner SCHMID1

1Gerhard Domagk Institut für Pathologie, University of Münster, Münster, Germany
2Department of Cranio-Maxillofacial Surgery, University of Münster, Münster, Germany
3Department of Surgery I, University Hospital, Innsbruck, Austria


Until recently the only way to rescue masked epitopes in routinely processed surgical pathological material was enzymatic digestion. The use of heat for antigen retrieval, first by microwave irradiation, represents an important breakthrough in immunohistochemistry. With the acceptance of microwave oven pretreatment, various modified techniques and alternative heating methods have also been proposed. Wet autoclave pretreatment for tissue proteolysis is a highly reliable alternative to the microwave antigen retrieval technique. It provides uniform heating of the slides, hence an even enhancement of staining intensity in a variety of formalin-sensitive antigens, and it also offers consistent interlaboratory results. The method has been introduced in routine diagnostic immunohistochemistry for the detection of estrogen- and progesterone receptors, L26-, Ki-67- and bcl-2 antigens and variable types of cytokeratins (1/5/10/11, 8, 13, 19). Experimentally, wet autoclaving can be used very successfully for the immunophenotyping of p53 and mdm2 expression, for the detection of adhesion molecules (CD44, integrins) and some anti-inflammatory molecules (annexins), among others. It has produced a substantial improvement in the visualisation of silver-stained nucleolar organizer regions- associated proteins (AgNORs) in routine paraffin sections and along with modified silver staining and standardized AgNOR parameters assessed by image analysis. Wet autoclaving-based AgNOR staining has been proposed by a European multicentric study group as the standardized method for AgNOR analysis in archival material. Pathology & Oncology Research, Vol 2, Nr 2, 71-77, 1996

Key words: Wet autoclave pretreatment; Immunohistochemistry; AgNOR

Received: Jan 6, 1996; accepted: Jan 21, 1996
Correspondence: Kurt Werner SCHMID, Gerhard Domagk Institut für Pathologie, University of Münster, Domagkstrasse 17 Münster D-48149, Germany; Tel: +49-251-835484, Fax: +49-251-835460

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