Biochemicals separation

Michael P. Thien/ Sc.D./ Senior Re.search Fellow, Merck Company, Inc. Member, American In stitute of Chemical Engineers, American Chemical Society, International Society for Pharmaceutical Engineering. (Selection of Biochemical Separation Proce.s.se.s)... 

FIGURE 4.18 Cation (a) and anion (b) exchange resins commonly used for biochemical separations. 

Besides discovering this method of resolution, Pasteur also discovered the method of conversion to diastereomers and separation by fractional crystallization and the method of biochemical separation (and, by extension, kinetic resolution). 

Hepatitis B vaccine is manufactured using recombinant DNA technology to express hepatitis B surface antigen (HBsAg) in yeast. This is further purified with biochemical separation techniques to produce the vaccine. The vaccines are formulated to contain 10 to 40 meg of HBsAg protein/mL. Hepatitis B vaccine is available as a single component or in combination vaccines. 

Although the general principles of separation processes are applicable widely across the process industries, more specialised techniques are now being developed. Reference is made in Chapter 13 to the use of supercritical fluids, such as carbon dioxide, for the extraction of components from naturally produced materials in the food industry, and to the applications of aqueous two-phase systems of low interfacial tensions for the separation of the products from bioreactors, many of which will be degraded by the action of harsh organic solvents. In many cases, biochemical separations may involve separation processes of up to ten stages, possibly with each utilising a different technique. Very often, differences in both physical and chemical properties are utilised. Frequently... 

According to biochemical separation, location, and substrate specificity, epoxide hydrolases (EH) have been divided into a number of groups. In mammals, the insoluble microsomal epoxide hydrolases and the soluble cytosolic epoxide hydrolases are enzymes of broad and complementary substrate specificity. 

Ng, G. Y., Trogadis, J., Stevens, J., Bonvier, M., O Dowd, B. F., and George, S. R. (1995) Agonist-induced desensitization of dopamine D receptor-stimnlated adenylyl cyclase activity is temporally and biochemically separated from D receptor internalization. Proc. Natl. Acad. Sci. U. S. A. 92, 10157-10161. 

It should be pointed out here that most biochemical separation methods that have been developed in research laboratories cannot necessarily be practiced on an industrial scale, so as to achieve high recovery levels. Rather, innovative approaches are often necessary in these industrial processes to achieve separations that ensure high purity and good recovery of the target product. 

Many problems in the analysis of biochemical separation techniques require the solution of a Fickian equation of the form... 

Ladisch, M R. Current Status and Ftnure Directions In Biochemical Separations, lecture at plenary session on Separation Science and Technologies New Developments and Opportunities II, paper 2 ccl997 AlChE Annual Meeting. Los Angeles CA, Nov. 17, 1997. 

The traditional methodology for the isolation of proteins involves biochemical separation techniques, whereby the protein of interest is isolated from all the other proteins based on its unique physical and chemical properties. This includes molecular weight (and hence size), shape (for example, globular versus rod), hydrophobicity, and net electric charge. 

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