Chinese hamster ovary cell production of recombinant tissue‐type plasminogen activator (t‐PA) was increased by amplification of cotransfected dihydrofolate reeducates cDNA using stepwise adaptation to increasing methotrexate (MTX) concentrations. The highest producing clones were isolated at 5 μM MTX and yielded 26,000 U/106 cells/day t‐PA (43 μg/106 cells/day). Above 25 μM MTX, cell specific t‐PA production rates became increasingly variable and the cDNA copynumbers decreased. No apparent correlation between the cell specific t‐PA production rate and the growth rate was observed upon sub cloning of the amplified cells. When MTX selection was removed, the t‐PA production rate decreased up to tenfold within 40 days; this was accompanied by an up to 60% drop in cDNA copynumber. Subclones isolated after 108 days of culture in the absence of MTX were, on average, sixfold more stable than their parental cells. In culture without MTX, the maximum stable t‐PA production rate obtained (over 250 days) was 7000 ± 750 U/106cells/day (∼12 μg/106 cells/day), approximately threefold lower than the maximum unstable levels of production reached under selective pressure. Taken together, these results define a wide range of the highest t‐PA expression rates obtained under MTX selection, for which stable expression without selection has not been reported
Answer:
flagella and cilia
Explanation:
Flagella (singular = flagellum) are long, hair-like structures that extend from the plasma membrane and are used to move an entire cell, (for example, sperm, Euglena).
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False. Your body contains trillions of cells but they don'y all carry out the same function. You need different cells for different functions otherwise we probably wouldn't be alive. LOL
Answer:
The main role of inorganic compound in microbes is the generation of energy in the form of Adenine tri phosphate (ATP) that is required for the growth and reproduction of microorganisms.
Explanation:
Inorganic compound are those in which carbon atom is absent. Many microorganisms especially bacteria, use inorganic compound such as ammonia, hydrogen, ferrous and sulfur etc for the production of energy that is used in different processes and activities such as reproduction and growth.
If the statue is like Lady Liberty, and overgoes a change in color and state. For example, she was originally copper, but later changed into patina due to weather such as acid rain, it is mechanical weathering. Please let me know if this helped.
