Animal Cell Culture Book Pdf Free Download

This article mainly addresses the issues associated with the engineering of large-scale free suspension culture in agitated bioreactors >10,000 L because they have become the system of choice industrially. It is particularly concerned with problems that become increasingly important as the scale increases. However, very few papers have been written that are actually based on such large-scale studies and the few that do rarely address any of the issues quantitatively. Hence, it is necessary very often to extrapolate from small-scale work and this review tries to pull the two types of study together. It is shown that 'shear sensitivity' due to agitation and bursting bubbles is no longer considered a major problem. Homogeneity becomes increasingly important with respect to pH and nutrients at the largest scale and sub-surface feeding is recommended despite 'cleaning in place' concerns. There are still major questions with cell retention/recycle systems at these scales, either because of fouling, of capacity or of potential and different 'shear sensitivity' questions. Fed-batch operation gives rise to cell densities that have led to the use of oxygen and enriched air to meet oxygen demands. This strategy, in turn, gives rise to a CO(2) evolution rate that impacts on pH control, pCO(2) and osmolality. These interactions are difficult to resolve but if higher sparge and agitation intensities could be used to achieve the necessary oxygen transfer, the problem would largely disappear. Thus, the perception of 'shear sensitivity' is still impacting on the development of animal cell culture at the commercial scale. Microcarrier culture is also briefly addressed. Finally, some recommendations for bioreactor configuration and operating strategy are given.

Background: Cell culture technology has spread prolifically within a century, a variety of culture media has been designed. This review goes through the history, characteristics and current issues of animal-cell culture media.

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Results: At the dawn of cell culture technology, the major components of media were naturally derived products such as serum. The field then gradually shifted to the use of chemical-based synthetic media because naturally derived ingredients have their disadvantages such as large batch-to-batch variation. Today, industrially important cells can be cultured in synthetic media. Nevertheless, the combinations and concentrations of the components in these media remain to be optimized. In addition, serum-containing media are still in general use in the field of basic research. In the fields of assisted reproductive technologies and regenerative medicine, some of the medium components are naturally derived in nearly all instances.

Conclusions: Further improvements of culture media are desirable, which will certainly contribute to a reduction in the experimental variation, enhance productivity among biopharmaceuticals, improve treatment outcomes of assisted reproductive technologies, and facilitate implementation and popularization of regenerative medicine.

Human food produced by this firm from cultured animal cells must meet the same stringent FDA requirements, including facility registration and applicable safety requirements, as other food. In addition, the firm will need a grant of inspection from the United States Department of Agriculture's Food Safety and Inspection Service (USDA-FSIS) for the manufacturing establishment. The food itself also requires a mark of inspection from USDA-FSIS before it can enter the U.S. market. As this product comes closer to entering the U.S. market, we are closely coordinating with USDA-FSIS to ensure it is properly regulated and labeled.

The FDA is ready to work with additional firms that are developing cultured animal cell food and production processes to ensure their food is considered safe and lawful under the Federal Food, Drug, and Cosmetic Act. We encourage firms to engage with us often and early in their product and process development phase, well ahead of making any submissions to the agency. The FDA will issue guidance to assist firms that intend to produce human food made from cultured animal cells prepare for pre-market consultations, and the published draft of this guidance will represent a formal opportunity for public comment and discussion. As we continue to support innovation in food technologies, resulting in more choices for consumers in the marketplace, our priority is the safety of food produced through both new and traditional methods.

While the primary subject of the meeting was focused on food safety, FDA recognizes the importance of other issues related to foods produced through animal cell culture technology, such as labeling, and FDA welcomed comment on these other issues and expects that they will be the focus of future engagement with stakeholders and the public. We intend to share our initial thinking for how we intend to appropriately apply our existing regulatory tools and policies to this novel area of technology. In addition, we plan to leverage the expertise of the FDA Science Board during their regular scheduled meeting in October to further inform our efforts.

When the recent coronavirus pandemic hit, laboratories throughout the world resolved to shut down operations, reduce the scale of work, or proceed at full steam. To safeguard the health of our scientists, ATCC has adopted a battery of best practices that minimize transmission of SARS-CoV-2 with little impact on productivity. Whether returning after a hiatus or gearing up for a new project, we can all use a refresher to help follow best practices. Please read this first section of the culture guide for some quick reminders about common contamination hotspots and advice on how to keep them in check while getting your work done.

ATCC cell line Product Sheets that contains detailed information for handling the cells may be found at the ATCC website or contact ATCC Technical Support to request a copy. The Product Sheet also contains batch-specific information such as the number of cells per vial, the recommended split or subcultivation ratio, and the passage number when known.

Prepare for reviving cell lines by assembling the appropriate medium, serum, and additional reagents required for growth. Many of these products are available from ATCC and can be ordered with the cell lines. These are the same reagents used by ATCC for cell growth and preservation. (See: NOTE 1)

Upon receiving a flask culture, visually examine the medium for macroscopic evidence of microbial contamination. This includes unusual pH shifts (yellow or purple color from the phenol red), turbidity, or particles. With an inverted microscope at low power (100) check the medium for evidence of microbial contamination as well as the morphology of the cells. See more details on examining cell cultures.

Most cell lines begin as primary cultures originating from a piece of minced or enzyme-dispersed tissue. Primary cultures, as mixtures of several cell types, retain the characteristics of their source tissue.

After a period of time, primary cultures will reach confluency, the state when all available space of the culture vessel is covered due to cellular expansion. At this point, the culture will need to be disaggregated (usually with proteolytic enzymes like trypsin) into individual cells and subcultured (split, passaged, or transferred). Following this first passage, the culture is generally referred to as a cell line. With each subsequent subculture, the cellular population becomes more homogeneous as the faster growing cells predominate. Cells with desired properties can also be selected out of the culture by cloning.

Diploid cell lines rarely progress beyond a few population doublings. They have a finite replicative capacity and begin to slow down and eventually stop dividing after 20 to 80 population doublings.1 Recent evidence suggests that some of the observed cellular senescence in cell culture may be due to inappropriate culture conditions as opposed to a predetermined replicative senescence.2 Still other data support replicative senescence for the cells of some species (notably human) even when grown in improved culture conditions. This senescence is mediated by the shortening of the ends of the chromosomes (telomeres) with each cell division.3

In contrast, continuous (or immortalized) cell lines have infinite replicative capacity. These lines are derived from cell lines through immortalization or transformation by any one of a number of means. Many continuous cell lines were derived from tumor tissue. Most of the cell lines in the ATCC collection are continuous, though a few, such as CCD-1117Sk human skin fibroblast (ATCC CRL-2465) or CCD-18Co human colon (ATCC CRL-1459) are finite.

As noted in the section on culture vessels, cell lines grow either attached to a surface (anchorage dependent) or in suspension (anchorage independent). As cells grow and divide in a monolayer or in suspension, they usually follow a characteristic growth pattern composed of four phases: Lag, log or exponential, stationary or plateau and decline.

To ensure viability, genetic stability, and phenotypic stability, cell lines need to be maintained in the exponential phase. This means that they need to be subcultured on a regular basis before they enter the stationary growth phase, before a monolayer becomes 100% confluent or before a suspension reaches its maximum recommended cell density. Generating a growth curve for each cell line is useful to determine the growth characteristics of the cell line. (See: Figure 1)

For detailed information on the growth and propagation of any ATCC cell line, see the specific cell line Product Sheet which can be found on the ATCC website, or contact ATCC Technical Support to have one sent to you.

Primary cultures are generally subcultured at a 1:2 ratio (they are split in half with each passage). Most continuous cell lines replicate at higher rates and are subcultured at a much higher split ratio. Passage number is generally the number of times the cells have been subcultured into a new vessel. For diploid cultures, passage number is roughly equal to the number of population doublings (or population doubling level, PDL) since the culture was started. This is not the case for continuous cell lines as they are passaged at higher split ratios. Consequently the PDL is not determined for continuous cell lines. In most cases, the PDL is an estimate as it does not account for any cells that were lost due to death from necrosis or apoptosis or cells which are nearing senescence and no longer divide. Calculate the population doubling level with the following formula: 2351a5e196