Kerosene: Contributing agent to xylene as a clearing agent in tissue processing

Abstract

Background:Research methodology in oral and maxillofacial pathology has illimitable potential. The tissue processing involves many steps of which one of the most important step is “Clearing,” which is a process of replacing dehydrant with a substance which is miscible with embedding medium or paraffin wax. Xylene is one of the common clearing agents used in laboratory, but it is also hazardous. The main aim of this study is to substitute conventionally used xylene by a mixture of kerosene and xylene in clearing steps without altering the morphology and staining characteristics of tissue sections. This will also minimize the toxic effects and tend to be more economical.Materials and Methods:One hundred and twenty bits of tissue samples were collected, each randomly separated into 4 groups (A, B, C and D) and kept for routine tissue processing till the step of clearing; during the step of clearing instead of conventional xylene, we used mixture of xylene and kerosene in 4 ratios ([A-K:X – 50:50]; [B-K:X – 70:30]; [C – Ab. Kerosene]; [D – Ab. Xylene – as control]) and observed for the light microscopic study adopting H and E staining, IHC (D2-40), Special stains (periodic acid–Schiff and congo red) procedure. The result was subjected to statistical analysis by using Fisher's exact test.Results:The results obtained from the present study were compared with control group, i.e., D and it was observed that Groups A and B were absolutely cleared without altering the morphology of tissue and cellular details; optimum embedding characteristics and better staining characteristics were also noted, whereas Group C presents poor staining characteristics with reduced cellular details. Embedded tissues in Group C presented with rough, irregular surface and also appeared shrunken.ConclusionCombined mixture of xylene and kerosene as a clearing agent in different ratio, i.e., Group A (K:X – 50:50) and B (K:X – 70:30) can be used without posing any health risk or compromising the cellular integrity.

Kerosene as an alternative to xylene in histopathological tissue processing and staining: An experimental study

“…However, the results were contrary to those of Shah et al . [7] Our study showed no changes in the morphology without any shrinkage in both group A and group B. We observed that increasing the clearing time in kerosene improves the quality of sectioning and also clearing.…”

“…In this study, we used kerosene as a safe alternative to xylene in tissue processing and staining without altering the tissue morphology and staining characteristics. In a study conducted by Shah et al .,[7] mixtures of kerosene and xylene were used in different ratios (70:30) and (50:50) with a time period of 2 hours for tissue processing. But still the presence of xylene renders harmful side effects.…”

“…Similarly in case of staining, Shah et al . [7] observed that mixture of kerosene and xylene in the ratio of 50:50 and 70:30 showed good nuclear and cytoplasmic morphology, clarity, uniformity, and crispness of staining. On the contrary, in our study, kerosene showed better nuclear and cytoplasmic morphology, clarity, uniformity, and crispness of staining.…”

Standard techniques for formalin-fixed paraffin-embedded tissue: A Pathologist’s perspective

“…Many clearing agents were used and applied during the clearing step, such as xylene, chloroform, cider wood oil, benzene, clover oil, carbon tetrachloride, and toluene (40). To address a simple comparison between these clearing agents (Table 3), explains the advantages and disadvantages of these clearing agents (41). One of the most common errors were associated with clearing steps with lipids in cells and tissues; these chemical components were dissolved by these agents, especially xylene, leave space inside tissue with different shapes and sizes (42).…”

Cedarwood oil as an alternative to xylene as a clearing agent in histopathological tissue processing – A comparative study

“…Xylene is a gold standard chemical that has been widely used as a clearing agent due to its ease of use, economic viability, effortless processing and an array of histological techniques that can be performed. [ 2 ]…”