Which solvent is used to remove lipids from tissue sections?

• A. Hot chloroform
• B. Ethanol
• C. Xylene
• D. Acetone

Answer: (A)

Lipids are nonpolar, so removing them requires a solvent that can dissolve fats and oils. Hot chloroform does this effectively because of its nonpolar character, and heating increases the lipid solubility and diffusion from the tissue, making the extraction faster and more complete. Ethanol and acetone are polar solvents and are better suited for dehydration or fixation steps rather than lipid dissolution. Xylene is mainly used for clearing and preparing tissue for paraffin infiltration and is not the primary agent for lipid extraction. Therefore, hot chloroform is the most effective choice for removing lipids from tissue sections. Safety note: chloroform is hazardous and should be used in a fume hood with appropriate precautions.