Long-term multiplication of the Chinese hamster ovary (CHO) cell line in a serum-free medium

1985 ◽  
Vol 21 (10) ◽  
pp. 588-592 ◽  
Author(s):  
Francois Gasser ◽  
Philippe Mulsant ◽  
Michel Gillois
Keyword(s):  
Cell Line ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster ◽  
Serum Free Medium ◽  
Free Medium ◽  
Cho Cell ◽  
Serum Free ◽  
Cho Cell Line

scholarly journals Rational development of a serum-free medium and fed-batch process for a GS-CHO cell line expressing recombinant antibody

2012 ◽  
Vol 65 (3) ◽  
pp. 363-378 ◽  
Author(s):  
Huifeng Zhang ◽  
Haibin Wang ◽  
Mei Liu ◽  
Tao Zhang ◽  
Ji Zhang ◽  
...  
Keyword(s):  
Cell Line ◽  
Recombinant Antibody ◽  
Batch Process ◽  
Serum Free Medium ◽  
Free Medium ◽  
Fed Batch ◽  
Cho Cell ◽  
Serum Free ◽  
Rational Development ◽  
Cho Cell Line

scholarly journals Mutant strain of Chinese hamster ovary cells with no detectable ornithine decarboxylase activity.

1985 ◽  
Vol 5 (6) ◽  
pp. 1385-1390 ◽  
Author(s):  
P Pohjanpelto ◽  
E Hölttä ◽  
O A Jänne
Keyword(s):  
Cell Line ◽  
Mutant Strain ◽  
Ornithine Decarboxylase ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster ◽  
Decarboxylase Activity ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Mutant Cells

We previously described an arginase-deficient, polyamine-dependent Chinese hamster ovary cell line which grows in serum-free medium. From this strain we isolated a new mutant strain that has no detectable catalytic ornithine decarboxylase activity. The mutant cells contain, however, immunoreactive ornithine decarboxylase-like protein roughly in the same quantity as the parent strain. The mutant and the parent cell line strains also contain similar amounts of ornithine decarboxylase-mRNA hybridizable to a specific cDNA. If polyamines are omitted from the medium, proliferation of the mutant cells is considerably retarded and ceases in 6 to 10 days. Addition of ornithine or alpha-difluoromethylornithine, a specific inhibitor of ornithine decarboxylase, has no effect on these cells. Putrescine and spermidine decreased in the mutant cells to undetectable levels during polyamine starvation, whereas spermine was reduced to 1/5th of that found in the control cultures. Polyamines appear to be indispensable for the mutant strain, but this was obvious only after the amount of polyamines, found as impurities in bovine serum albumin used in the medium, was reduced by dialysis to 10(-12) M. Because sera contain polyamines, the ability of the mutant strain to grow in serum-free medium is a great advantage in elucidation of the mechanisms of polyamine function.

Mutant strain of Chinese hamster ovary cells with no detectable ornithine decarboxylase activity

1985 ◽  
Vol 5 (6) ◽  
pp. 1385-1390
Author(s):  
P Pohjanpelto ◽  
E Hölttä ◽  
O A Jänne
Keyword(s):  
Cell Line ◽  
Mutant Strain ◽  
Ornithine Decarboxylase ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster ◽  
Decarboxylase Activity ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Mutant Cells

We previously described an arginase-deficient, polyamine-dependent Chinese hamster ovary cell line which grows in serum-free medium. From this strain we isolated a new mutant strain that has no detectable catalytic ornithine decarboxylase activity. The mutant cells contain, however, immunoreactive ornithine decarboxylase-like protein roughly in the same quantity as the parent strain. The mutant and the parent cell line strains also contain similar amounts of ornithine decarboxylase-mRNA hybridizable to a specific cDNA. If polyamines are omitted from the medium, proliferation of the mutant cells is considerably retarded and ceases in 6 to 10 days. Addition of ornithine or alpha-difluoromethylornithine, a specific inhibitor of ornithine decarboxylase, has no effect on these cells. Putrescine and spermidine decreased in the mutant cells to undetectable levels during polyamine starvation, whereas spermine was reduced to 1/5th of that found in the control cultures. Polyamines appear to be indispensable for the mutant strain, but this was obvious only after the amount of polyamines, found as impurities in bovine serum albumin used in the medium, was reduced by dialysis to 10(-12) M. Because sera contain polyamines, the ability of the mutant strain to grow in serum-free medium is a great advantage in elucidation of the mechanisms of polyamine function.

Discrete electrophoretic products of mitochondrial protein synthesis in the Chinese hamster ovary cell line

1977 ◽  
Vol 55 (10) ◽  
pp. 1064-1074 ◽  
Author(s):  
R. W. Yatscoff ◽  
K. B. Freeman
Keyword(s):  
Protein Synthesis ◽  
Cell Line ◽  
Electrophoretic Mobility ◽  
Chinese Hamster Ovary ◽  
Mitochondrial Protein ◽  
Chinese Hamster ◽  
Mitochondrial Proteins ◽  
Mitochondrial Protein Synthesis ◽  
Cho Cell ◽  
Cho Cell Line

Mitochondrial proteins labelled with [35S]methionine for 1 h in whole Chinese hamster ovary (CHO) cells in the presence of cycloheximide or emetine, known inhibitors of cytosolic protein synthesis, have been enumerated and characterized by their electrophoretic mobility in sodium dodecyl sulfate slab gel electrophoresis. Ten distinct electrophoretic bands were observed. The components were relatively stable during a 2 h postlabelling period. The same 10 bands were also seen with the CHO cell line tsH1, labelled at 40 °C, a temperature at which cytosolic but not mitochondrial protein synthesis is inhibited in this cell line, and with isolated mitochondria labelled in the presence of cycloheximide. An 11th band was present when [3H]leucine but not [35S] methionine was used for labelling. The width of the major band suggested that it consists of two components making a total of at least 12 proteins synthesized in mitochondria. The molecular weights of these mitochondrial proteins ranged from 5000 to 50000 and there was a sixfold difference in the relative molar amounts synthesized in a 1-h period in the presence of [3H]leucine or [3SS] methionine.No differences in number or electrophoretic mobility of the mitochondrially synthesized proteins were found among the seven CHO cell lines examined. These results suggest the stability of the mitochondrial genome in the CHO cell line.

scholarly journals Controlling Ratios of Plasmid-Based Double Cut Donor and CRISPR/Cas9 Components to Enhance Targeted Integration of Transgenes in Chinese Hamster Ovary Cells

2021 ◽  
Vol 22 (5) ◽  
pp. 2407
Author(s):  
Sung Wook Shin ◽  
Dongwoo Kim ◽  
Jae Seong Lee
Keyword(s):  
Cell Line ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Cho Cell ◽  
Cell Line Development ◽  
Cho Cell Line ◽  
Vector Systems ◽  
Targeted Integration

Chinese hamster ovary (CHO) cells are the most valuable expression host for the commercial production of biotherapeutics. Recent trends in recombinant CHO cell-line development have focused on the site-specific integration of transgenes encoding recombinant proteins over random integration. However, the low efficiency of homology-directed repair upon transfection of Cas9, single-guide RNA (sgRNA), and the donor template has limited its feasibility. Previously, we demonstrated that a double-cut donor (DCD) system enables highly efficient CRISPR/Cas9-mediated targeted integration (TI) in CHO cells. Here, we describe several CRISPR/Cas9 vector systems based on DCD templates using a promoter trap-based TI monitoring cell line. Among them, a multi-component (MC) system consisting of an sgRNA/DCD vector and Cas9 expression vector showed an approximate 1.5-fold increase in knock-in (KI) efficiency compared to the previous DCD system, when a systematically optimized relative ratio of sgRNA/DCD and Cas9 vector was applied. Our optimization efforts revealed that concurrently increasing sgRNA and DCD components relative to Cas9 correlated positively with KI efficiency at a single KI site. Furthermore, we explored component bottlenecks, such as effects of sgRNA components and applicability of the MC system on simultaneous double KI. Taken together, we improved the DCD vector design by tailoring plasmid constructs and relative component ratios, and this system can be widely used in the TI strategy of transgenes, particularly in CHO cell line development and engineering.

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