Evaluation of biosafe alternatives as xylene substitutes in hematoxylin and eosin staining procedure: A comparative pilot study

BACKGROUND: Xylene is synthetic hydrocarbon produced from coal tar known for its wide usage as universal solvent which has many hazardous effects. The aim of this study is to compare the efficacy of xylene-free hematoxylin and eosin (H and E) sections with conventional H and E sections. MATERIALS AND METHODS: The study included ninety paraffin-embedded tissue blocks. Of these, sixty blocks were processed with sesame oil (xylene alternative) and thirty blocks with xylene. The study sample was divided into three groups. Sixty sections which are taken from sesame oil-processed blocks were stained with xylene-free H and E staining method. In xylene-free staining method, 95% diluted lemon water (Group A) and 1.7% dish washing solution (DWS, Group B) were used as deparaffinizing agents whereas the remaining 30 sections were processed with xylene and stained with conventional H and E staining method (Group C). Slides were scored for the following parameters: (i) nuclear staining (adequate = score 1, inadequate = score 0), (ii) cytoplasmic staining (adequate = score 1, inadequate = score 0), (iii) uniformity (present = score 1, absent = score 0), (iv) clarity (present = score 1, absent = score 0) and (v) intensity (present = score 1, absent = score 0). Score ≤2 was considered inadequate for diagnosis while scores 3–5 were considered adequate for diagnosis. RESULTS: Adequate nuclear staining was noted in 90% of sections of Group A and 100% each in Group B and Group C (P < 0.05); adequate cytoplasmic staining in 96.7% in Group A and 100% each in Group B and Group C (P > 0.05); adequate uniformity of staining in 53.3% of sections of Group A, 70% in Group B and 83.3% in Group C (P < 0.05); adequate clarity of staining in 73.3% sections of Group A, 80% in Group B and 83.3% in Group C (P > 0.05) and adequate intensity of staining in 76.7% sections of Group A, 93.3% in Group B and 100% in Group C (P < 0.05). Group C sections stained adequate for diagnosis (93.3%) followed by Group B (88.7%) and Group A (78%; P < 0.05). CONCLUSION: Tissues processed with sesame oil and stained using 1.7% DWS were found to be effective alternative to xylene.