Production Modules

Figure 44.42 Product modulation fora speed-increaser gearbox...

At 1 14 p.m., the operator received a radio transmission from the PCC (Process Control Center) informing him that a "low" gas alarm had been received. Immediately, the operator was informed of two more gas alarms. Upon reaching the E l module, the operator noted the sound of gas escaping somewhere inside the production module. At approximately 1 22 p.m. he climbed the stairs to the E l control room and opened the door to check the fire and gas alarm panel which indicated a high gas atmosphere in the production modules. The operator then requested the Emergency Response Team be put on standby and went to inform three contract workers, in the area of the danger. 

The E l module did not have gas detection which, if located in the air intake, would have significantly reduced the probability of an explosion. Gas detectors should be fitted in the HVAC supply to all nonhaz-ardous areas where ingress of released hydrocarbon gas is credible. There was no automatic production shutdown from fire or gas (F G) detection in production modules. 

GastroPlus Simmulation Plus Inc. http //www.simulations-plus.com/ products/module metabolism.html. 

MiniPERM classic kit, molecular weight cutoff 12.5 kDa/vol 35 mL. Kit comprises 12 production modules, single packed, sterile four nutrient modules, reusable four stands for the MiniPERM bioreactor (cat. no. IV-76001055 Vivascience, Sartorius AG Weender Landstrasse 94-108, 37075 Goettingen, Germany). 

Fig. 2. Schematic view of the MiniPERM production module. Reproduced with permission from Joachim Liicke.

The hybridomas and secreted antibody are retained in the production module (Fig. 2). Depending on the cell line, cell densities can reach upwards of 1 x 107 cells/mL. The MiniPERM bioreactor is rotated on a universal turning device that allows four MiniPERM bioreactors to be run simultaneously for larger production runs of one hybridoma or production of different hybridomas. This motion speeds the distribution of nutrients to the cells and facilitates the removal of metabolic waste products and C02, processes that rely on passive diffusion in static bioreactors. Sample collection and harvesting is via Luer-Lock connections on the production module. The MiniPERM is a continuously fed culture system that allows cultures to be maintained for several weeks. 

After sampling and harvesting the Luer-Locks must be wiped down with 70% ethanol to prevent infection being introduced to the production module see Note 20). Periodical measurement of cell density, viability, and antibody production during the course of the production run will help in the planning of future production runs. 

Preassembled sterile bioreactors are available from the manufacturer. With the classic kit, the production modules are sterile and can be used just once, the nutrient module needs to be assembled and sterilized. 

Spare Luer-Lock screw caps for production modules six pieces, single packed, sterile (cat. no. IV-76077027 Vivascience). 

Assemble the MiniPERM bioreactor according to the manufacturer s instructions (see Note 9), disinfect the universal roller, and install in a C02 incubator. Media for the production module (production medium) and the nutrient module (nutrient medium) should be prepared before the inoculation (see Notes 1-4). The production medium is complete medium as described previously but supplemented with a further 5% FBS and 0.1% v/v CellPROTECT (see Note 10). The nutrient medium contains the same components as complete medium, with the exceptions of 5% FBS instead of 10% FBS and with the addition of 0.2% v/v AntiFOAMa (see Note 11). Both the nutrient media and the production media are prewarmed to 37°C to prevent expansion of the MiniPERM membrane when introduced into the incubator. 

Draw the suspension slowly up into a 50-mL hypodermic syringe (see Note 13). Unscrew the two Luer-Locks on the assembled MiniPERM and inject the cell suspension carefully into the production module while the module is slowly rotated (see Note 14). This ensures that displaced air is expelled through the open Luer-Lock. 

Some hybridomas require a higher concentration of FBS, up to 15%. As the cells in the production module are subject to shearing forces owing to the rotation of the bioreactor, CellPROTECT can be used as an antishearing supplement. 

Nutrient medium is supplemented with 5% fetal bovine serum. Low molecular weight serum proteins diffuse across the dialysis membrane between the nutrient and production modules. A reservoir of low molecular proteins is required in the nutrient module to maintain the equilibrium for hybridoma growth and survival. Accumulation of foam in the nutrient module can be a problem. To counteract foaming, do not exceed a concentration of 5% FBS in the nutrient module and add AntiFOAMa antifoaming agent. Do not fill the nutrient module with more than 400 mL of nutrient medium. An air space is required within the module to ensure successful hybridoma growth. 

The whole process consists of a sequence of consecutive steps which allows separation into production modules. Some of them already exist and will just need slight modifications. Others have to be developed. At the very beginning, one makes use of the newly developed reel-to-reel etching technology for micro structured stainless-steel foils similar to the process described in [166], The structured foils are then coated with catalyst, structured again with a laser tool and finally folded by sheet metal forming to a reactor monolith. The readily mass-produced reactors will be sealed by laser welding. 

The complete manufacturing is divided into a number of production modules, e.g. for coating, laser structuring and reactor mass-producing. This facilitates the identification of possible defects in the production line and also permits parallel development. 

Marumo, T., Schini-Kerth, V.B., Fisslthaler, B., and Busse, R. 1997. Platelet-derived growth factor-stimulated superoxide anion production modulates activation of transcription factor NF-kappaB and expression of monocyte chemoattractant protein 1 in human aortic smooth muscle cells. Circulation 96 2361-2367. 

H Umezawa (1980) Screening of small molecular microbial products modulating immune responses and bestatin, Recent Results Cancer Res 75 115-125... 

Singhal PC, SagarS, Reddy K, Sharma P, Ranjan R, Frank N. HIV-1 gpl 20 envelope protein and morphine-tubular cell interaction products modulate kidney fibroblast proliferation. J Invest Med 1998 46 243-248. 

A few products modulate operation of the skin s appendages. These include antiperspirants (as opposed to deodorants), which use the astringency of chemicals such as aluminum chloride so as to reversibly irritate and close the orifices of eccrine glands... 

Table 2 Helminth products modulating host immune response... 

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