Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085631 (agitation)
 12,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A mechanical device for the continuous purification of biological material using immunosorbent was developed. The system consists of heat-sealed nylon pouches containing agarose-bound antibody, attached to an endless 35 mm wide Mylar belt that passes through four chambers sequentially. The biological material is bound and dissociated, and the immobilized antibody is regenerated for repeated isolation and purification of antigen. The belt design incorporates features to minimize carry-over between chambers and prevent damage to the agarose-bound antibody in repeated passes through the system. An existing batch method for the purification of human placental alkaline phosphatase using immobilized rabbit antisera was adapted to continuous purification in the device. The belt contained a low affinity immunosorbent and made five complete passes through the system. A decrease in antigen binding capacity between free immunosorbent suspensions and belt immunosorbent in pouches was observed. This was shown to be the result of the diffusion resistance offered by the pouch and the short exposure times of each pouch in the chambers. A decrease in antigen binding capacity between successive belt passes was also observed, and resulted from the inability of the agarose in the pouches to resuspend completely after each pass. The low efficiency of the agitation method and the roller device used to squeeze the pouches were the reasons for this deficiency.
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PMID:Method for continuous purification of biological material using immunosorbent. 37 86

Secreted human placental alkaline phosphatase (SEAP) was produced in a nonengineered Trichoplusia ni insect cell line, Tn-4s, using a recombinant Autographa californica baculovirus expression vector. The effect of culture conditions on SEAP specific yield and glycosylation was studied. When cultured in the high aspect ratio vessel (HARV) or in tissue culture flasks (T-flasks), baculovirus-infected Tn-4s cells produced high levels of SEAP (13 and 23 U/10(6) cells, respectively; 4 days postinfection), but in those conditions SEAP possessed only high mannose, paucimannosidic, and hybrid structures. In spinner flasks, lower SEAP yields were obtained (<4 U/10(6) cells, 3 days postinfection), but in such cultures, sialylation of SEAP could be achieved. Several spinner-flask culture conditions were tested and resulted in different SEAP specific yields and levels of sialylation. The highest level of sialylation (9%) was obtained in the culture with the lowest agitation rate and lowest yield (1.2 U/10(6) cells), suggesting a limiting capacity of the Tn-4s cells to process glycoproteins to sialylation. High specific yield, low passage number Tn5B1-4 cells did not produce SEAP with complex glycosylation when cultured in a low agitation rate spinner-flask. On the basis of these results, we propose that the Golgi apparatus has a limited capacity for processing proteins to complex glycosylation and sialylation and that this capacity is easily overwhelmed by high levels of foreign protein productivity. Selected media additives such as Pluronic F-68, dextran sulfate (MW 12 500) and a lipids premix did not allow improvement of the specific yield of sialylated SEAP when supplemented to spinner-flask cultures.
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PMID:Effect of culture conditions on the degree of sialylation of a recombinant glycoprotein expressed in insect cells. 1279 Jun 33