HOW TO EXAMINE THE ANTIGEN-DAMAGING EFFECT OF SODIUM ETHOXIDE ON DEPLASTICIZED EPOXY SECTIONS

The purpose of this investigation was to develop a method that could b e used to estimate how damaging sodium ethoxide is to different antige ns with respect to immunolabeling when epoxy sections are deplasticize d. If we obtain weak labeling for an antigen on deplasticized epoxy se ctions, this might be caused by the damaging effect of the ethoxide so lution. It is therefore interesting to develop a method to check if th is really is the reason. Fibrin clots and tissues of human kidney and thyroid were embedded in LR White resin. Some thin sections from these specimen blocks were exposed to sodium ethoxide in the same way as ep oxy sections are when being deplasticized. Other sections from the sam e blocks were not exposed to sodium ethoxide. Both categories of secti ons were immunogold-labeled with anti-fibrinogen, anti-thyroglobulin, anti-IgA, anti-IgG, or anti-IgM. The intensity of immunolabeling of se ctions treated with ethoxide was compared with the immunolabeling of c orresponding sections that were not treated with ethoxide. No signific ant differences were found in immunolabeling for fibrinogen, IgA, IgG, and IgM. For thyroglobulin, the intensity was approximately 30% less in tissues that were exposed to sodium ethoxide. The practical signifi cance of this method is that we easily can examine the degree to which a given antigen is affected by sodium ethoxide, which is the agent us ed for deplasticizing epoxy sections.