Paraffin wax is an inert mixture of long-chain hydrocarbons produced from petroleum processing. Three changes are recommended during processing with this. Which description is accurate?

• A. It is a water-based resin
• B. It is an inorganic salt
• C. It is an inert mixture of long-chain hydrocarbons produced from petroleum processing
• D. It is a natural wax from bees

Answer: (C)

Paraffin wax serves as the embedding medium in histology and is defined by its composition and origin: an inert mixture of long-chain hydrocarbons produced from petroleum processing. This makes it hydrophobic and chemically stable, so it doesn’t react with tissue components during processing and sectioning. Its petroleum origin and hydrocarbon makeup are what allow it to melt and infiltrate tissues at moderate temperatures and then solidify to form firm blocks for thin sectioning. The other options don’t fit because paraffin is not water-based, not an inorganic salt, and not beeswax (which is a natural wax from bees with a different composition).