Dimethyl carbonate replaces xylene in paraffin section as a biosafe and effective transparent reagent.

Paraffin section is an important technique in histology research, and transparency is the key step connecting the procedures of dehydration and wax immersion in paraffin sectioning technology. However, the commonly used transparent reagent xylene is toxic to the human body and the environment and included in the list of carcinogens. Few biosafe and environmentally friendly transparent reagents have been widely used to replace xylene. In this study, we found a green transparent reagent, dimethyl carbonate (DMC). Physical and chemical analysis showed that DMC was nontoxic and biodegradable. The feasibility analysis of DMC as a substitute for xylene showed that DMC improved the quality of wax band, staining quality, cell boundary, cell morphology, and section integrity in the sections of plant and animal tissues. The toxicological analysis showed that DMC had no significant effect on the key organs of mice, did not induce obvious inflammation in vivo, and showed higher biosafety than xylene. DMC can be used as a transparent reagent to replace xylene in paraffin section, based on its better physical properties, better paraffin sectioning effect, and higher biosafety. DMC is expected to be widely used in the technical fields of tissue section through further optimization and improvement of the method.