Evaluation of the efficacy of hematoxylin and eosin stain when xylene is completely replaced by turpentine or kerosene oil - A comparative study for oral tissues.

Background: Microscopic examination of cells and tissues requires the preparation of very thin and good-quality sections mounted on glass slides and appropriately stained to demonstrate normal and abnormal structures. Before this step, the tissue must undergo preparatory treatment known as tissue processing. The various stages of tissue processing are dehydration, clearing, impregnation, and embedding, each with a particular duration for proper completion of the process. Xylene is the most frequently used clearing agent whose carcinogenic potential is well documented. Hence, attempts were made to substitute xylene with a biosafe clearing agent. The present study aimed to evaluate and compare the efficacy of hematoxylin and eosin stain (H and E stain) when xylene is completely replaced by turpentine or kerosene oil.

Materials and methods: A total number of 50 tissue samples were taken in the study, which included 40 study samples and 10 controls. All the samples were randomly separated into three groups and routine tissue processing and H and E staining were performed. The result was further subjected to statistical analysis by using Fisher's exact test. Group-1: Ten tissue samples were processed and H and E staining was done in xylene. Group-2: Twenty tissue samples were processed and H and E staining was done in turpentine oil. Group-3: Twenty tissue samples were processed and H and E staining was done in kerosene oil.

Results: Nuclear staining, cell morphology, and uniformity of staining were better in kerosene sections, while cytoplasmic and clarity of staining of turpentine sections were comparable with xylene sections.

Conclusion: Turpentine and kerosene as clearing agents can be used in the future with certain modifications in their concentration and routine staining protocol.