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

Abstract

Abstract INTRODUCTION: Deparaffinization and clearing prior to coverslipping are important steps in all staining methods in histopathology. Xylene is the most commonly used agent worldwide. However, xylene is toxic. We evaluated safer alternative dewaxing and clearing agents prior to coverslipping in a histopathology laboratory. MATERIALS AND METHODS: Thirteen different fresh surgical tissues were cut into two halves. One half processed using xylene and the other half processed using UltraClear™. Five groups were designed. For each Group of A, B, C, and D, 100 slides were cut from xylene-processed blocks. For Group E, 100 slides were cut from UltraClear™-processed blocks. Group A is the standard method. Group B evaluates UltraClear™ as a dewaxing agent only. Group C evaluates UltraClear™ as a clearing agent prior to coverslipping only. Group D evaluates UltraClear™ as both dewaxing and clearing agents prior to coverslipping. Group E evaluates UltraClear™ as both dewaxing and clearing agents prior to coverslipping. Six parameters were evaluated: nuclear staining, cytoplasmic staining, cell morphology, clarity of staining, uniformity of staining, and cost. RESULTS: Groups B, C, and D showed 79% (P = 0.054), 83% (P = 0.221), and 80% (P = 0.079) adequacy when compared with Group A (89%), respectively. However, Group E showed only 76% (P = 0.016) adequacy. UltraClear™ is more expensive than xylene. CONCLUSION: UltraClear™ is a promising dewaxing agent. It is also a good clearing agent for use prior to coverslipping in histopathology laboratory. Cost-benefit balance between safety of laboratory workers, good quality staining, and cost-effective strategy needs to be further studied.