Abstract:

Background: Xylene was used as a clearing and dewaxing agent during routine tissue processing in histopathology laboratories. Despite its excellent clearing property, xylene is associated with adequate amount of toxicity. Therefore, various substitutes for xylene have been explored such as mineral oil and vegetable oil mixtures. This study aimed at assessing the efficacy of bleached vegetable oil as a dewaxing agent due to this we can observe if the vegetable oil may be used as an alternative for xylene due to its harmful hazardous effects to the laboratory user.

Objectives: To compare the dewaxing ability of bleached vegetable oil to that of xylene in routine hematoxylin and eosin staining procedure.

Materials And Methods: Laboratory based cross-sectional study on archived tissue blocks (n= 133) retrieved from BMC histopathology, morbid anatomy department was done and each block was cut into two sections. During dewaxing procedure, each tissue section was subjected into two dewaxing agents namely bleached vegetable oil (sunflower oil) and xylene. The effectiveness for each was estimated in percentage on final H&E-stained slides and parameters such as transparency of the tissues, nuclear and cytoplasmic staining properties were assessed between the two groups.

Results: For overall tissue clarity 96.2% sections dewaxed with xylene and 75.2% sections dewaxed with bleached sunflower oil showed good results while 3.8% sections dewaxed with xylene and 17.3% sections dewaxed with bleached sunflower oil showed satisfactory results. Furthermore, 7.5% sections dewaxed with bleached sunflower oil showed poor results. For nuclear staining quality, 72.9% sections dewaxed with xylene and 44.4% sections dewaxed with bleached sunflower oil showed good results while 27.1% sections dewaxed with xylene and 49.6% sections dewaxed with bleached sunflower oil showed satisfactory results. Furthermore, 6.0% sections dewaxed with bleached sunflower oil showed poor results.

For cytoplasm staining quality, 72.9% sections dewaxed with xylene and 54.9% sections dewaxed with bleached sunflower oil showed good results while 27.1% sections dewaxed with xylene and 39.1% sections dewaxed with bleached sunflower oil showed satisfactory results. Furthermore, 6.0% sections dewaxed with bleached sunflower oil showed poor results.

Conclusion: From this study, bleached vegetable (sunflower) oil can be used as safer substitute for xylene in H and E staining procedure.