Vegetable oils instead of xylene in tissue processing

Abstract

In an effort to improve working conditions in the histopathologic laboratory, we have investigated whether less toxic substances may be substituted for the toxic organic solvent xylene currently in use. Xylene is used in the clearing as well as the deparaffinization process. We have tested whether the substitution of xylene by olive oil and coconut oil leads to any difference in the quality of the histologic sections. Two tissue blocks from each of 232 specimens sent for histopathologic evaluation were subjected to parallel processing in xylene and oil. The specimens represented a broad spectrum of tissue types. All sections were stained with hematoxylin‐eosin to permit evaluation of histologic and cytologic details. Furthermore, a range of histochemical and immunohistochemical stainings were applied to a subgroup of tissue sections. The results showed qualitative differences between xylene‐processed and oil‐processed tissue in only a minority of cases. In no cases were the oil‐processed samples considered less suitable for histologic diagnosis. In the histochemical and immunohistochemical stainings, no differences were registered. Although the long‐term stability of oil‐processed tissue remains to be clarified, we conclude that less toxic vegetable oil may probably be substituted for xylene without losing valuable diagnostic information.

Comparing the efficacy of coconut oil and xylene as a clearing agent in the histopathology laboratory

“…and they noted incomplete impregnation, leading to problems in the cutting sections and therefore, they concluded that this mixture was ineffective as a clearing agent. [ 20 ] In contrast to their observation, we found that CO-S, when used alone, was as effective as xylene, without interfering with further impregnation and cutting. This difference could be because of the olive oil in the mixture, which would have adversely affected the procedure, counteracting with the favorable properties of coconut oil.…”

“…Considering the toxicity of xylene and its hazards, various substitutes, including vegetable oils and mineral oils, have been tried in the past. [ 11 16 19 20 21 22 23 ] However, most of them showed an inconsistent outcome, which motivated us to take up this study. Coconut oil was selected, as it is, profusely available in the tropical world, especially in South Asia, it is less expensive and non-hazardous.…”

“…[ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ] On account of the Occupational Safety and Health Administration (OSHA) regulations, various xylene substitutes, such as, limonene reagents, aliphatic hydrocarbons, vegetable oils and mineral oils were tried in the past to avoid xylene in the laboratory. [ 11 16 19 20 21 22 23 ] However, these substitutes were found to be less effective and more expensive. Coconut oil is a commonly used vegetable oil, available throughout the tropical world.…”

A substitute to xylene in deparaffinization and clearing prior to coverslipping in histopathology

“…[1] Similar findings were reported with coconut and olive oils as substitutes for xylene during clearing and dewaxing. [13]…”

Olive oil as xylene substitute

“…Because of new regulations from Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA), [1][2][3][4][5][6][7][8][9] several xylene substitutes such as limonene reagents, aliphatic hydrocarbons, vegetable oils and mineral oils have been commercially developed in recent years. [10][11][12][13] However these commercially available xylene substitutes are less effective, more expensive, and not much less hazardous than xylene itself. Coconut and olive oil are commonly used vegetable oils available throughout the tropical world.…”