What is the most effective way to purify proteins?

Proteins can be purified in accordance with such characteristics as size, solubility, charge and binding affinity. When purifying a single protein from a complex protein mixture, more times than not a series of separation steps, each based on a different characteristic, is used until a pure protein is yielded. After each step in your purification scheme, remember to determine the protein concentration. While several factors may need to be considered before determining the best purification scheme, the most important factor to consider is the overall yield of your purification scheme. The higher the conjugation yield the better the purification scheme.

Over the years several purification techniques have been developed, these include:

• Salting Out
• Dialysis
• Gel-Filtration Chromatography
• Ion-Exchange Chromatography
• Affinity Chromatography
• High-Pressure Liquid Chromatography

Of the aforementioned techniques, affinity chromatography is one of the most widely used purification schemes because of its robustness. This technique exploits the high affinity of many proteins for a specific chemical group.

References:

Berg JM, Tymoczko JL, Stryer L. Biochemistry. 5th edition. New York: W H Freeman; 2002. Section 4.1, The Purification of Proteins Is an Essential First Step in Understanding Their Function. Available from: https://www.ncbi.nlm.nih.gov/books/NBK22410/