A PARAFFIN EMBEDDING TECHNIQUE FOR STUDIES EMPLOYING IMMUNOFLUORESCENCE

TLDR

The study presents a tissue fixation method for immunofluorescence and recommends testing new antigens or antibodies before adoption. The method fixes thin tissue blocks in 95 % ethanol, dehydrates and clears them at 4 °C, then embeds in paraffin and sections using standard microtomy. Compared to frozen sections, the technique provides more precise antigen localization, higher detection sensitivity, and longer persistence of bovine serum albumin, and it successfully preserves several antigens including bovine gamma globulin, horse ferritin, influenza A virus, diphtheria and tetanus toxoids, though it fails with hen's ovalbumin.

Abstract

A method is described for the fixation of blocks of tissue for use in studies employing immunofluorescence. This method consists of fixing thin blocks in 95% ethanol and carrying out the subsequent dehydration and clearing at refrigerator temperatures (4°C). Thereafter, embedding in paraffin and sectioning by the standard microtomy is easy. This method results in preparations which are histologically more precise in the localization of antigen or antibody than preparations of frozen tissues; and with rabbit antibody and bovine serum albumin, the sensitivity of detection is enhanced. Bovine serum albumin can be found for longer periods after injection than is possible with frozen sections. Other antigens for which this procedure has proved satisfactory are bovine gamma globulin, horse ferritin, influenza A virus, diphtheria and tetanus toxoids. Hen's ovalbumin deteriorated. New antigens or new antibodies should be tested before being committed to this method.