Centrifugal precipitation chromatography, a powerful technique for the isolation of active enzymes from tea leaves (Camellia sinensis) J. Chrom. A Special Edition CCC 2008

This paper is another multifaceted gem in the Special Edition. Not only are the authors exploring CCC instrumentation and methodology, but they are applying this technology to the isolation and purification of viable enzymes. A special coil has been manufactured whereas the two channels for “sample” and “solvent” can be separated with a semi-permeable membrane such as a dialysis membrane. The column is eluted in a true countercurrent process where the phases move in opposite directions and at different flow rates. In this case, the composition of the “sample” phase remains constant while the “solvent” phase is run with an acetone to buffer gradient. The acetone has the effect of replacing the buffer in the “sample” phase with acetone and effectively salting-out proteins. The portion of the sample phase that has been exposed to the solvent phase the longest has the highest concentration of acetone. As the acetone proportion decreases in the solvent phase the proteins in the sample phase solubilize and are eluted.

As you have already surmised, this barely resembles the classic pre-equilibrated continuous liquid-liquid extraction technique that most of us know CCC/CPC to be. It occurs to me that there are really two issues here. The first is the membrane-assisted CCC/CPC separation. The second is the specific application of this membrane technology to classical protein precipitation and dialysis. What I am saying is that the particular technology need not be restricted to precipitation. It may, in fact, have some interesting applications as new membranes are constantly being developed for various applications. Maybe we will see a CCC/CPC fuel cell soon! Surprisingly, the authors do not speculate on what acronym may be used to designation Centrifugal Precipitation Chromatography. How about CPreC?