Abstract: The invention concerns a process for purifying protein A preparations to high purity with high product yield. Where the protein A is obtained from a Gram-negative recombinant microbe hosting a vehicle containing a gene encoding protein A, the protein A is purified to high purity, and, advantageously, to very low levels of endotoxin. The protein A preparations made via the invention process are useful in therapeutic application, e.g., therapeutic plasma exchange, as well as for other well-known uses of protein A.

Abstract: A method for recovering a recombinant protein from a protein solution containing high molecular weight contaminating proteins by directly adding Group IIA metal salts to the solution in amounts sufficient to selectively precipitate the high molecular weight protein contaminants is disclosed.The high molecular weight precipitates are removed and the solution is further processed to remove low molecular weight contaminating proteins and other non-protein contaminants. The recombinant protein is subsequently recovered and further processed to produce a protein composition suitable for its intended use.

Abstract: The present invention comprises a method for the purification of the 69 kDa outer membrane protein of Bordetella B. pertussis and the protein purified therewith. A preferred embodiment comprises the purification of the 69 kDa protein from Bordetella B. pertussis strain Bp 353. The present process is advantageous in that it does not require or involve the use of biologics (such as monoclonal antibodies) and therefore simplifies the purification procedure and makes the resulting purified protein particularly advantageous for inclusion in acellular vaccines.

Abstract: There is disclosed a method for purifying a gene-expression product produced by recombinant DNA technique which comprises a specific sequence of steps including adsorption treatment with silica gel, adsorption treatment with activated carbon, at least twice density gradient centrifugation and at least twice equilibrium density gradient centrifugation. The method of the present invention is very effective to remove allergen from gene-expression products contaminated therewith, enabling highly purified gene-expression products to be produced on a large scale.

Abstract: The invention relates to a method for the purification of the a subunit of factor XIII by affinity chromatography, to a therapeutic composition containing the latter, and to the use of the therapeutic composition.Factor XIII has hitherto been purified either by methods which are technically very elaborate or else by use of toxic affinity chromatography materials. The invention has the aim of providing an improved method for the purification of the a subunit of factor XIII.Factor XIII is obtained according to the invention by a method in which the a subunit of factor XIII is reversibly bound to a matrix suitable for disulfide exchange reactions and is removed from the matrix by reaction with a reducing agent. The method according to the invention makes it possible to provide the biologically active a subunit of factor XIII in high purity.

Abstract: Processes are provided for producing purified, hepatitis B surface antigen particles in mammalian cells which comprise culturing mammalian cells which produce the particles in a culture medium supplemented with a serum free of high molecular weight contaminant proteins and recovering the purified, hepatitis B surface antigen particles.Removal of molecules having a molecular weight greater than about 3.times.10.sup.5 daltons by prefractionation, for example, allows cells to be grown in culture media containing high levels of fetal calf serum, removes high molecular weight contaminant proteins which may be inhibitory to cell growth and simplifies purification of HBsAg since high molecular weight contaminant proteins are the major contaminants removed by purification processes.

Abstract: A process for the preparation of a spatial form, which has biological activity, of a protein from a biologically inactive spatial form is described and comprises the protein being dissolved with the addition of a denaturing agent and thus converted into the random coil form, and the solution being allowed to pass through a material which has molecular sieve properties and contains a liquid medium in which the protein can assume a spatial form which has biological activity, and this material having molecular sieve properties being selected so that the molecules of the denaturing agent can penetrate, but the protein molecules canot. It is possible by centrifugation, blowing or sucking out to remove the medium in the "external volume" of the molecular sieve and to increase the rate of passage of the solution through the molecular sieve.

Abstract: This invention relates to a process for continuously fractionating plant, animal or human proteins by selective precipitation of the proteins resulting from placing a solution of proteins in contact with a precipitating agent constituted by a fatty acid of 6 to 14 carbon atoms, such as caprylic acid, is characterized in that respective deliveries of fatty acid and of the protein solution are continuously placed in contact in a mixing chamber of small volume with respect to the deliveries, creating a strong stirring in this mixing chamber; the individual deliveries of fatty acid and of protein solution are adjusted to controlled pH and temperature so as to maintain their ratio equal to a predetermined value; the mixture is then allowed to evolve during a phase of maturation so as to form a suspension; this suspension is separated into a liquid part from which are extracted the proteins having remained soluble, and a solid part containing proteins of different nature; and the parameters intervening in the proce