Abstract: A method for precipitating casein from a suspension comprising milk is disclosed. The method includes the following steps: adding a phosphate solution to a suspension; mixing the phosphate solution with the suspension to form a mixture having a phosphate concentration greater or equal to 40 mM; freezing the mixture having a phosphate concentration greater or equal to 40 mM to obtain a frozen mixture; and thawing the frozen mixture to obtain casein-containing aggregates in the mixture, in which the phosphate solution is buffered at a pH value of no less than 4.4.

Abstract: Methods for separating casein from soluble proteins in a composition. The method includes: adding a phosphate solution to the composition, mixing to form a mixture, freezing the mixture to obtain a frozen mixture, thawing the frozen mixture to obtain casein-containing aggregates in the mixture, and then centrifuging the mixture to obtain a supernatant traction and a casein-precipitate fraction. The supernatant fraction contains the soluble protein, which may be isolated by subjecting the supernatant fraction to a purification process. The method can be applied to purify a recombinant protein from the milk of a transgenic mammal.

Abstract: The present invention refers to a method of separating casein from animal milk, especially, after defatting the animal milk as the pretreatment, the processing of the defatted milk aforesaid through a ceramic filtration membrane to remove the casein in the milk. The pretreatment process of separating the casein from the milk is then complemented by other processes of purification, so as to obtain the target protein of higher purity.

Abstract: The present invention relates to a nucleic acid construct encoding hirudin and a transgenic mammal whose genome comprises the nucleic acid construct as well as a process for producing hirudin from the transgenic mammal.

Abstract: The present invention discloses a method for expressing multiple recombinant proteins in transgenic non-human mammalian milk, characterized in which human clotting factor IX gene and porcine lactoferrin gene are transferred into the mammal by gene injection and embryonic implantation to obtain expression in the milk of transgenic mammal and its filial generation. The method of this invention can maintain the stable expression of multiple recombinant proteins in the transgenic mammal during lactation and stable expression amount proximate to that of the first generation in the offsprings of the transgenic non-human mammal.

Abstract: The present invention discloses a method for expressing multiple recombinant proteins in transgenic non-human mammalian milk, characterized in which human clotting factor IX gene and porcine lactoferrin gene are transferred into the mammal by gene injection and embryonic implantation to obtain expression in the milk of transgenic mammal and its filial generation. The method of this invention can maintain the stable expression of multiple recombinant proteins in the transgenic mammal during lactation and stable expression amount proximate to that of the first generation in the offsprings of the transgenic non-human mammal.

Abstract: The present invention refers to a method of separating casein from animal milk, especially, after defatting the animal milk as the pretreatment, the processing of the defatted milk aforesaid through a ceramic filtration membrane to remove the casein in the milk. The pretreatment process of separating the casein from the milk is then complemented by other processes of purification, so as to obtain the target protein of higher purity.