Boehringer Mannheim Gmbh

Michael J Comer

Michael J Kearns

Christoph Kessler

Herbert Jungfer

Gunther Schumacher

Bryan J Bolton

Friedrich Popp

Georg Nesch

Michael J Munster

Ulrich Steegmans

Bodo Seydler

The invention presents a method for the culturing of mammalian cells. This method involves the use of a bioreactor, which contains a sample of mammalian cells in a culture medium containing large molecules. Positioned inside the bioreactor is a semipermeable membrane which defines a space separated from the bioreactor by the semipermeable membrane. A nutrient medium flows through this separated space and, via virtue of the semipermeable nature of the separating membrane, nutrient pass therethrough into the culture medium, while cellular waste products pass into the separated space. The semipermeable membrane is selected so that the cells and large molecules, such as proteinaceous materials, cannot pass through the membrane, but remain in the bioreactor.

Method for mammalian cell culture

Process for inactivation of recombinant DNA

A process for culturing biological material capable of multiplication, especially cells securely adhering to microcarriers, employs a bioreactor having a vessel for a culture medium having means for controlling the environmental conditions in the culture medium and a stirring device for the homogeneous distribution of the cells in the culture medium which has a rotary drive and a rotation axle running in the interior of the vessel, wherein the stirring device has at least one flat stirrer blade fixed on to the rotation axle and inclined to the rotation axle.

Process for culturing biological material

The present invention teaches restriction endonuclease Asp 718 which cleaves DNA in the palindromic recognition sequence at the sites indicated by the arrow: ##STR1## The endonuclease, obtained from Achromobacter species 718, DSM 2969, is useful in obtaining DNA fragments, e.g., for determining nucleotide sequences and other types of analysis of DNA.

Restriction endonuclease cleaving palindromic DNA

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Bernried, Germany

Michael J Comer