Recovery after cell lysis

Operating conditions and the corresponding performance of a membrane filter system have been examined for recovering proteins from a bacterial lysate. Specifically, the dependence of membrane flux on average trans membrane pressure and recirculation rate has been investigated for both whole cells and lysate. The recovery of an intracellular protein was simulated by adding a marker protein, IgG, to the lysate after cell lysis. 

Product manufacture entails viral vector propagation in a suitable animal packing cell line (known as HEK 293). After cell recovery and lysis, the crude product is clarified by filtration and concentrated by ultrafiltration. The product is then treated with a nuclease preparation in order to degrade contaminant DNA and further downstream processing entails multi-step high-resolution column chromatography (see also Figure 14.7). 

Extracellular Products. In order to prevent cell lysis, removal of cells from a fermentation broth is usually started within hours after harvest. After cell separation, the clarified fermentation broth is more stable and can be stored refrigerated for days. Upon harvest, most primary recovery steps involve some pretreatment of the fermentation broth, which can range from simple cooling and dilution for fungal broths to pH adjustments, addition of salts, stabilizers, or flocculation agents in order to minimize degradation of the desired product and facilitate further processing. For labile compounds, such as protease enzymes,... 

Metal fume fever is commonly encountered among industrial workers exposed to zinc fumes, and is characterized by pulmonary irritation, fever, chills, and gastroenteritis. Attacks begin 4-8 h after exposure, and recovery in 24-48 h. The pathogenesis of metal fume fever is unknown, but may be associated with endogenous pyrogens released by cell lysis. Rabbits, rats, and cats exposed to zinc oxide fumes for 3.5 h at concentrations of 110.0-600.0mg/m reacted with a transient fall in body tenpera-ture followed by leucocytosis heavily exposed animals had signs of bronchopneumonia. The atmospheric threshold limit value (TLV) for zinc is 5.0mg/m however, results of studies... 

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