Research Highlight

Green process for purifying protein, DNA

doi:10.1038/nindia.2015.144 Published online 29 October 2015

Researchers have synthesized green organic solvents that could be used to concentrate low-abundance biomolecules such as proteins and DNA from a mixture of biomolecules, facilitating further purification and extraction1. Their technique is potentially attractive for extracting pure proteins and DNA for clinical research and the food industry.

Because proteins and DNA are sensitive to temperature and pressure fluctuations, it is extremely difficult to maintain their structural integrity during purification processes. To overcome this problem, the researchers synthesized organic solvents by separately heating and stirring mixtures of choline chloride and ethylene glycol and of choline chloride and glycerol. They then probed the efficiencies of the solvents to purify bovine serum albumin and a specific fish DNA using a membrane-based forward osmosis process.

The scientists found that the solvents increased protein and DNA concentrations more effectively than existing commercial solvents. As the technique does not exert pressure or thermal stress on the biomolecules, it should be an ecofriendly way to purify proteins and DNA.

It was possible to separate and reuse the solvent made from choline chloride and ethylene glycol by cooling the mixture to –5 degrees Celsius. The recovered solvent could be reused many times for purifying proteins.

This technique employs organic solvents that are used as food ingredients, making it potentially useful for biomedical and food-processing industries, the researchers say.


1. Mondal, D. et al. Deep eutectic solvents as new class of draw agent to enrich low abundant DNA and proteins using forward osmosis. RSC Adv. 5, 89539–89544 (2015)