Method for purification and concentration of synthetic biological molecules

摘要

The present invention is an ultrafiltration (UF) membrane having a nominal molecular weight cutoff (NMWCO) of from about 0.5 KD to about 10 KD wherein the membrane surfaces have a charge that is either positive or negative. The present invention is also a method of using the charged UF membrane to purify and concentrate synthetic biological molecules by using the charged surface either to repel the synthetic biomolecules retaining them in the retentate or to attract the synthetic biomolecules preferentially for filtration through the membrane. The charge of the membrane can be adjusted by means of the pH of the feed solution.