What is the primary agent used for deparaffinization?

The primary agent used for deparaffinization is xylene. This organic solvent is widely utilized in histology to remove paraffin wax from tissue specimens after embedding. When tissues are sectioned for microscopic examination, they are typically embedded in paraffin wax to maintain structural integrity. However, before any staining can occur, this paraffin needs to be removed to allow reagents, such as stains and mounting media, to penetrate the tissue sections.

Xylene is highly effective for this purpose due to its ability to dissolve paraffin efficiently. Its use in the deparaffinization process ensures that the tissue sections are adequately prepped for further analysis and staining, making it an essential step in histological workflows.

Formalin and paraformaldehyde are fixatives used in preserving tissues prior to embedding and do not play a role in removing paraffin. Ethanol, while commonly used in various laboratory procedures, is not the primary choice for deparaffinization. Instead, it is typically utilized in dehydration steps, often preceding embedding in paraffin but not directly for removing the paraffin itself.