Fc-fusion Protein Purification Using Oversized Chromatography Columns? – A different purification strategy.

It is quite normal to see low titer recombinant protein feedstreams, such as Fc fusion protein, especially during early stage drug research and discovery. To obtain enough purified recombinant proteins, a large volume of feedstream is usually needed. Take a Fc-fusion protein as an example. Suppose the Fc-fusion protein has a titer of 10 mg/L. One may need purify 200 mL stream. The total target amount of Fc-fusion protein is 2 milligrams.

Protein A columns may have a dynamic binding capacity (DBC) of 15-20 mg Fc-fusion protein/mL. A Protein A column of 1 mL should be sufficient. However, there is speed limitation on resin chromatography columns, which will make the purification ridiculously long. In addition to taking up footprint and manhours, long purification times may also hurt molecule stability.

Often times, people may use an oversized Protein A column (5 mL in this hypothetical) and run it at 10 mL/min to save time and maintain sufficient binding capacity. One purification cycle can be done in an hour. Although there is time saving, it costs more $ than it should.

In addition, your sample is still very diluted because of a pretty large elution pool.

We are proposing a different strategy to purify low titer high volume recombinant proteins. Purilogics has developed Purexa™ PrA seires protein A membrane chromatography columns. In the example above, we suggest one use a 0.2 mL Protein A column. It can maintain decent binding capacity at 10 mL/min – 20 mL/min. Although there may not be time saving, one can save $ on the smaller column ($100/column, save time on processing, and obtain much more concentrated eluate.

If you are interested, please check Purexa™ PrA webpage. Feel free to contact us if you have any questions!