Exchange gels

Weakly acidic cation exchangers—gel type—carboxylic acid functionality... 

The higher intensities /3 measured for ion exchanged gels (gels prepared by procedure b) comparing to /3 of gels prepared by procedure a, are probably the result of the different silica source used. It was found that gels prepared from sodium silicate contain... 

Rebif is produced via recombinant DNA technology in a CHO cell line. It displays an identical amino acid sequence to that of native human IFN-P-la and, like the native product, is glycosylated. After cell culture the interferon is purified using a series of chromatographic steps (affinity, ion-exchange, gel-filtration and reverse-phase liquid chromatography). It is formulated as a sterile solution in pre-filled syringes and contains mannitol, HSA, sodium acetate, acetic acid and sodium hydroxide as excipients. It is administered subcutaneously three times weekly. 

Table 26-2 Common active groups of ion-exchange gels...

Consider a negatively charged protein adsorbed on an anion-exchange gel at pH 8. 

Selection of type of chromatography (partition, adsorption, ion exchange, gel exclusion). 

In principle, h.p.Lc. arose from conventional liquid column chromatography, following the development of g.l.c. and realisation that it was a rapid and accurate analytical method. This led to a reappraisal of the liquid column chromatographic system, which in turn resulted in research developments in instrument design and in the manufacture of column-packing materials. These now have precise specifications to make them suitable for adsorption, normal and reversed phase partition, ion exchange, gel permeation, and more recently affinity chromatography. 

HPLC is suitable for SVOCs/POMs that cannot be analyzed with GC due to their stability and/or low vapor pressure. HPLC is a more complicated technique than GC since there are many more parameters to vary (stationary phase, solvent, solvent compositions, solvent gradient, temperature etc.) and has relatively high running expenses due to the solvent use. A number of separation methods can be used in HPLC, for example ion exchange, gel filtration, normal phase and reversed phase. HPLC has lower resolution than GC but offers different separation techniques for special purposes as well as several detection techniques. 

Fluther purification of the crude enzyme preparations obtained after extraction often involves multiple chromatographic steps including ion-exchange, gel... 

Protein A Ion exchange Gel filtration Good selectivity very low productivity of... 

Cation exchange Gel filtration — Good productivity first poor productivity with... 

Protein A Cation exchange gel filtration Good selectivity good binding capacity high cost... 

II. ADAPTABILITY OF ABSORPTION SPECTROMETRY FOR ANALYSIS OF THE ION-EXCHANGER GEL PHASE... 

Once the ApK and Vq terms for the ion exchanger gels are dehned at specific Cs and a values, i.e., at specified p[H] values, then the respective values for a metal ion, are calculable by use of the two terms together with the unique (Pi)d value. To demonstrate this capability the... 

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