Abstract: An improved method for producing Factor VIII:c is disclosed. The method involves culturing mammalian cells which contain DNA encoding Factor VIII:c and which are capable of expressing Factor VIII:c. In accordance with this invention the cells are cultured in a medium containing an effective amount of a Factor VIII:c-stabilizing substance comprising (a) von Willebrand Factor (VWF), (b) a phospholipid or phospholipid mixture, or a mixture of (a) and (b).

Abstract: Eucaryotic cells cotransformed with product and selection genes yield considerably greater quantities of product after a novel subcloning strategy is employed: Transformants are identified for product yield, cultured under selection pressure and the progeny screened for product yield. Novel transformation vectors contain directly ligated selection and product genes and/or eucaryotic promoters.

Abstract: Hybrid procoagulant proteins are disclosed which contain peptide sequences of human blood coagulation factors V and VIII. DNA molecules encoding these proteins and materials and methods for expressing them are also disclosed. Preferably, peptide sequence in the B domain of Factor VIII is replaced with peptide sequence derived from human Factor V.

Abstract: Eucaryotic host cells are disclosed which contain a DNA molecule encoding an eIF-2.alpha. mutant and preferably a DNA sequence encoding a desired heterologous protein. The DNA sequences are linked to expression control sequences permitting expression of the mutant eIF-2.alpha. gene and the heterologous gene. Culturing such cells provides a method for the production of the desired heterologous protein. The mutations eliminate one or both serine residues at positions 48 and 51 of the eIF-2 sequence. In another aspect of the invention, the eIF-2 5'-untranslated sequence was observed to have effects on translation of heterologous mRNAs.

Abstract: This invention provides vectors, improved host cells and improved methods for producing a heterologous protein by culturing an improved eucaryotic host cell of this invention transformed or transfected with a vector capable of directing the expression of the heterologous protein. The preferred improved host cell of this invention is a mammalian host cell containing and capable of expressing an anti-sense GRP78 DNA sequence.

Abstract: High yields of active Factor IX are produced by culturing a CHO cell line transfected with chromosomally-integrated Factor IX cDNA in medium to which vitamin K is added.

Abstract: Eucaryotic cells cotransformed with product and selection genes yield considerably greater quantities of product after a novel subcloning strategy is employed: Transformants are identified for product yield, cultured under selection pressure and the progeny screened for product yield. Novel transformation vectors contain directly ligated selection and product genes and/or eucaryotic promoters.

Abstract: A method for identifying and isolating clones containing DNA coding for a desired protein is described. DNA prepared from a cell that expresses the desired protein is inserted into an isolation expression vector having means for replication (as a means of producing DNA) and a suitable promoter for expression of said DNA in a predetermined mammalian host cell as well as means for replication in a bacterial cell. The transient expression vector is then inserted into a bacterial cell for replication of the DNA. Pools of DNA, prepared from a predetermined number of bacterial clones so that the nucleic acids (DNA and RNA) is substantially free of other bacterial contaminants are transfected or microinjected into mammalian host cells and conditioned medium from growing such cells is tested for the presence of the desired protein. Positive pools are selected and the clones used to make the pool are screened to identify and isolate the clone containing the desired DNA.