Ernst Karl Weibel

The biofreezer, a new contained freezing equipment in biotechnology

SummaryThe Biofreezer has been designed for freezing biomass or cell-suspensions in the laboratory, pilot and large scale biotechnology under hygienic and biosafe conditions. The principle is based on the freezing of biomass drops on the surface of a liquid nitrogen bath to form small beads, which are harvested automatically. The application is presented as a part of the Roferon-A production (leukocyte interferon α-2a Roche), representing a physically contained system extending from 1000 l fermenter through continuous centrifugation to the frozen biomass beads. The freezing process in the Biofreezer is extremely fast and complete and the beads can be thawed instantaneously. Comparisons with other freezing systems are described.

Biosafety investigations in an r-DNA production plant.

Employees of a biotechnological production plant for recombinant interferonα-2a have been participating in a 1-year study on occupational hygiene and the resulting biosafety aspects. Most of the employees have been employed in the plant for more than 6 years. Weekly stool samples were analysed for tetracycline (used as selection marker)-resistant coliforms as well as for rDNA (IFN gene) (interferon gene) and for the production organism. Various analytical methods, including the polymerase chain reaction, were applied to show that neither rDNA nor the production organism could be found in any of the stool samples and that there was no change or trend in the gut flora with respect to tetracycline resistance. In addition it could be shown that the tetracycline-resistance gene, as well as the rDNA, are completely inactivated in the course of the production process and thus no further recombination can take place. Blood samples were taken to show that none of the employees had anti-product antibodies.

Biological safety considerations in the production of health care products from recombinant organisms

Safety considerations in the field of recombinant technology and rDNA production of health care products have been under discussion since the beginning of this technology in 1973 and will certainly go on. However no adverse effects, which could have been attributed to rDNA technology have been observed. On the other hand many life-saving and life-improving drugs have been on the market for many years to the benefit of many patients. New technologies and products thereof often provoke uncertainties about their impact on the environment or society. This article discusses some potential risks in the application of rDNA technology to drugs as well as some benefits for patients, society and environment.