Abstract: The invention relates to a method for the chromatographic purification of preproinsulins, in which higher molecular weight substances are removed from an aqueous solution of preproinsulin by a first chromatography on an anion exchanger in flow-through mode and a subsequent second chromatography on a cation exchanger in adsorption mode, and to a method for preparing insulins, which includes the method for preparing preproinsulins.

Abstract: The invention relates to a method for the chromatographic purification of preproinsulins, in which higher molecular weight substances are removed from an aqueous solution of preproinsulin by a first chromatography on an anion exchanger in flow-through mode and a subsequent second chromatography on a cation exchanger in adsorption mode, and to a method for preparing insulins, which includes the method for preparing preproinsulins.

Abstract: The invention relates to a method for the chromatographic purification of preproinsulins, in which higher molecular weight substances are removed from an aqueous solution of preproinsulin by a first chromatography on an anion exchanger in flow-through mode and a subsequent second chromatography on a cation exchanger in adsorption mode, and to a method for preparing insulins, which includes the method for preparing preproinsulins.

Abstract: The present invention relates to a process for drying protein crystals starting from an aqueous protein crystal suspension, which comprises drying the protein crystal suspension in a centrifugal dryer, where the protein crystals, after they have been filtered off from the protein crystal suspension, are brought into contact with a drying medium which consists of a mixture of water and a nonaqueous solvent which is miscible with water in any ratio and which has a lower vapor pressure than water. In the process, a drying gas which has been moistened with water is advantageously used. The protein crystal suspension is advantageously converted into a fluidized bed for the purpose of drying.

Abstract: What are disclosed are a method for preventing the denaturation of proteins such as insulin in aqueous solution at interfaces by the addition to the solution of a surface-active substance comprising a chain of alternating weakly hydrophobic and weakly hydrophilic zones, protein solutions containing such a surface-active substance, methods of purifying proteins contained in such solutions, and methods of treating surfaces with such a surface-active material to prevent the denaturation of proteins thereon.

Abstract: What are disclosed are a method for preventing the denaturation of proteins such as insulin in aqueous solution at interfaces by the addition to the solution of a surface-active substance comprising a chain of alternating weakly hydrophobic and weakly hydropholic zones, protein solutions containing such a surface-active substance, methods of purifying proteins contained in such solutions, and methods of treating surfaces with such a surface-active material to prevent the denaturation of proteins thereon.

Abstract: The invention relates to aqueous solutions of proteins with a molecular weight above 8,500 daltons, which contain a compound of the formula IR.sup.2 O--X.sub.n --R.sup.3 (I)in which X.sub.n is a chain of n members of the formula II or III ##STR1## in any desired sequence, n denotes 2 to 200 and R.sup.1 denotes hydrogen, methyl or ethyl, it being possible for the radicals R.sup.1 to be identical or different but R.sup.1 being hydrogen in at least half of the chain members, and R.sup.2 and R.sup.3 are identical or different and denote hydrogen or an organic radical, to processes for their preparation and to their use. The invention furthermore relates to the use of compounds of the formula I for the pretreatment of hydrophobic surfaces to avoid adsorption of denaturing of proteins.