Proteins grade

Economic Aspects. Halocarbon Products Corp. is the largest producer of trifluoroacetic acid. The commercial grade is of very high purity with the main impurity being ca 0.2% water. A grade, which has a low residue specification, intended for use in protein synthesis (Biograde) is available. Other producers include Rhc ne-Poulenc and Solvay. The 1992 price was ca 15/kg. 

Biomedical Applications. TRIS AMINO is used for a number of purposes in its pure form, it is an acidimetric standard the USP grade can be utilized intraveneously for therapeutic control of blood acidosis TRIS AMINO also is useful in genetic engineering as a buffering agent for enzyme systems, industrial protein purification, and electrophoresis. AMP has found use as a reagent in enzyme-linked immunoassays. The primary appHcation is for alkaline phosphatase assays. 

Membrane filtration has been used in the laboratory for over a century. The earliest membranes were homogeneous stmctures of purified coUagen or 2ein. The first synthetic membranes were nitrocellulose (collodion) cast from ether in the 1850s. By the early 1900s, standard graded nitrocellulose membranes were commercially available (1). Their utihty was limited to laboratory research because of low transport rates and susceptibiUty to internal plugging. They did, however, serve a useflil role in the separation and purification of coUoids, proteins, blood sera, enzymes, toxins, bacteria, and vimses (2). 

Sephadex type Grade Dry bead diameter (/urn) Fractionation range peptides and proteins (g/mol) Fractionation range dextrans (g/mol) Swelling factor (ml/g dry Sephadex) Maximum operating pressure" (cm H,0) Permeability Ko Maximum linear velocity" (cm/hr) Swelling time (h) ... 

If unidentified peaks are detected the stability of the protein under the chromatographic conditions should be checked. In all analytical investigations of proteins on SEC columns it is desirable to be able to monitor the eluted peaks at a very high sensitivity of the ultraviolet detector. Therefore, very pure (analytical grade) salts and buffers should be used. 

Takacs, B. J. and Girard, M.-F., Preparation of clinical grade proteins produced by recombinant DNA technologies,. Immunol. Meth., 143, 231, 1991. 

---