Olive oil as xylene substitute

Introduction: Clearing agents are among the most noxious and hazardous chemicals found in the histology laboratories. Therefore in an effort to improve working conditions in the histopathology laboratory, we have investigated whether non-toxic substances may be substituted for the toxic organic solvent xylene currently in use. Materials and Methods: Two tissue blocks from each 60 soft tissue specimen (anatomical structures in head and neck region) were subjected to parallel processing in xylene and olive oil. All the sections were stained with hematoxylin-eosin to permit evaluation of histologic details by two different observers. The collected data was subjected to statistical analysis using Wilcoxon matched pair test & Mann-Whitney u test. Results: The results showed no significant differences between the two different clearing agents in terms of gross tissue changes except for rigidity after clearing. Statistically significant gross tissue shrinkage evident in xylene was not seen in vegetable oil processed tissue. The cellular details were well preserved and the staining intensity was uniform. In the histochemical and immunohistochemical staining, no differences were registered. Morphometrically there was significant difference in mean area of epithelial (parabasal) cells and mucous acini in xylene processed tissues compared to that of olive oil. Conclusion: The overall results have demonstrated professional acceptance of olive oil as a substitute for xylene, without losing valuable diagnostic information. Keywords: Clearing agents, Xylene, Olive Oil, Histopathology, Immunohistochemistry.