Aliphatic hydrocarbons used as clearing agents are generally called what?

• A. Alkanes
• B. Aromatics
• C. Alkyl halides
• D. Aldehydes

Answer: (A)

Clearing agents that are aliphatic hydrocarbons belong to the saturated, nonpolar group known as alkanes. These are favored in tissue clearing because their nonpolar nature allows them to dissolve lipids and to mix easily with paraffin wax, helping to remove water and render the tissue transparent for embedding. Among aliphatic hydrocarbons, alkanes (paraffins) such as hexane or heptane are typical examples used as clearing agents. Aromatic hydrocarbons (like xylene or toluene) are also used in some protocols, but they belong to a different category of hydrocarbons, and the question specifically refers to the aliphatic class. Alkyl halides and aldehydes are not standard clearing agents in histology.