Conventional xylene and xylene-free methods for routine histopathological preparation of tissue sections

Xylene customarily has been used as a clearing agent for routine tissue processing. Because xylene is a relatively hazardous solvent, laboratories are under pressure to seek less toxic alternatives for routine use. We prepared 30 paired soft tissue specimens for routine histopathological evaluation using conventional xylene and xylene-free methods to evaluate and compare their efficacy for fixation, processing, embedding, staining and turnaround time. All specimens were measured before and after processing. Three pathologists evaluated and scored the histological sections. Tissue shrinkage was greater when using the xylene method compared to the xylene-free method. The quality of tissue sections including tissue architecture; quality of staining; preservation of epithelial, fibrous, glandular, muscle and adipose tissue; inflammatory cells; and vascular tissue was better after using the xylene method, but differences were not statistically significant. Xylene-free method produced adequate results that nearly equaled the xylene method. Added advantages included cost effectiveness, better working atmosphere and decreased toxicity.