COLD ACETONE FIXATION AND METHACRYLATE EMBEDDING - A SUITABLE METHOD FOR ROUTINE PROCESSING OF BONE-MARROW BIOPSIES

Here report that acetone fixation at -18 degrees C with subsequent emb edding in methyl-/butylmethacrylate is a reliable method for the routi ne processing of bone marrow biopsies. This method allows good convent ional histological visualization of morphological details, which is co mparable with other fixation procedures. The essential advantage of th is method is that a wide range of monoclonal antibodies and polyclonal antisera can be used for immunohistochemical investigations for diagn ostic and scientific purposes. The addition of 5% polyethylene glycol 400 to the acetone minimizes freeze-related artefacts. The immunohisto chemical demonstration of a number of antigens is mostly affected by t he medium used for slide preparation and to a lesser extent by the con centration of benzoylperoxide used for polymerization. Performing poly merization at 4 degrees C and using N, N-dimethyl-p-toluidine as accel erator allows the concentration of benzoylperoxide to be reduced to 0. 2 g% (8.3 mmol). Under these conditions the methacrylate embedding pro cedure has only minimal effects on the quality of immuno-and enzyme hi stochemistry. Additionally, the simplified method for re moving the po lymerization inhibitor from the methacrylate components and the shorte ned impregnation step are further advantages of the embedding method d escribed here.