Which solvent is commonly used for separation of biomolecules?

The separation of biomolecules such as proteins, nucleic acids, and enzymes is a crucial step in many biochemical and molecular biology experiments. Among different solvents, Trichloroacetic acid (TCA) is widely recognized as one of the most effective for this purpose.TCA is a strong organic acid that causes denaturation and precipitation of biomolecules. When TCA is added to a solution containing proteins or nucleic acids, it disrupts their normal three-dimensional structure by breaking hydrogen bonds and hydrophobic interactions. As a result, the biomolecules become insoluble and form a precipitate. This precipitate can then be separated using centrifugation or filtration methods.

One of the main advantages of using TCA is its efficiency and reliability. In protein studies, TCA is often employed for protein concentration prior to assays such as Lowry or Bradford. It is also applied in nucleic acid extraction procedures, making it a versatile reagent in laboratory work.

Let’s consider the other options for comparison:

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  Acetone: Sometimes used for dehydrating and partially purifying proteins, but it is not the primary solvent for biomolecule separation.

  
  


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  Ether: Used mainly as a laboratory solvent and historically as an anesthetic, but it does not effectively precipitate biomolecules.

  
  


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  Alcohol (ethanol or isopropanol): Common in DNA precipitation, but less effective for proteins compared to TCA.

  
  

Thus, while alcohols and acetone have limited uses in biomolecule isolation, TCA is the most widely accepted solvent for general separation of biomolecules because of its strong precipitating power and consistent results.

Key Fact: TCA is inexpensive, easy to use, and highly efficient, which is why it remains a standard solvent in biochemical laboratories.

✅ Therefore, the correct answer is Trichloroacetic acid (Option B).