Culture procedures

Theobromine levels in tea are considerably lower than those of caffeine. Little has been reported with regard to effect of variation in cultural procedures. Values range in manufactured tea from 0.16 to 0.20%32-33 on a dry-weight leaf basis. 

Culture procedures have been developed for a number of blood and tissue parasites, but these procedures are used primarily in research. The culturing of Leishmania spp. and Trypanosoma cruzi may be helpful for diagnosis, and the procedures are easy to use. 

Methods General tissue culture procedures are followed as previously described (34). Tumor cells and HUVECs are maintained in culture under standard conditions (37 °C, 5% CO, 95% humidity) and passaged when subconfluent. 

The cultivated potato and many of its relatives are amenable to eell and tissue culture procedures, ineluding protoplast isolation and fusion. Somatic cell fusions have frequently been used to eombine the genomes of Solarium speeies that are sexually ineompatible because of pollen-stylar interactions or mismatched EBN numbers. Somatic fusion circumvents sexual reproduetion and results in novel eombinations of not only nuclear genomes, but also cytoplasmic genomes (Trabelsi et al., 2005 Bidani et al., 2007 Lovene et al., 2007). However, recalcitrant genotypes... 

Scientifically this may have had some unforeseen effects in the fact that each national laboratory began to grow the vaccine under different cultural conditions from those laid down by the originators. The net result was that a number of different BCG vaccines, each identified by its country of origin, began to appear and, with hindsight, these different cultural procedures resulted in vaccines with different potencies. 

Fig. 7. Culture procedure and schematic diagram of embryo and plantlet regeneration from the immobilized callus...

Embryonic stem cell The embryonic stem cell line is typically derived from a male agouti 129/terSv embryo. The cell line must be maintained with meticulous culture procedures to retain normal karyotype and an undifferentiated state. 

Summers, M. D. Smith, G. E. A Manual of Methods for Baculoyirus Vectors and Insect Cell Culture Procedures 1987, Texas Agricultural Experiment Station Bulletin No. 1555. 

Cultured biological dressings are derived from mammalian cell culture procedures which facilitate the development of sheets of cells derived from a few of the patients own epidermal cells. Cultured human keratinocytes form cultured epithelial grafts that are not bioengineered tissues but are cultured cell products with limited use. These cultures may be regarded as a precursor which has led to the development of other products through bioengineering.t ... 

Rapid methods to detect pathogenic bacteria in food products are important alternatives to laborious and time-consiuning culture procedures. Many investigators have pubUshed papers on the use of electrochemical immunosensors for the identification and quantification of bacterial pathogens Escherichia coli 0157, Staphylococcus aureus, and Salmonella spp., which are common contaminants of food or water. 

Clearly the practical application of animal cell culture has to be underpinned by well-developed laboratory protocols. There are a significant number of cell culture procedures that are used across the broad range of ceU culture applications in both academic and industrial laboratories and frequently there are several methods that can be used to solve a given problem. 

As summarized in Fig. 1, the components that must be customized based on the application include cell source, scaffold parameters, and cell culture procedures. 

Cell Culture Procedures. All the data reported in these studies were from cultures grown in 125 mL shake flasks containing 25 mL of media in a New Brunswick G24 rotary shaker at 37 0.2 C and 250 rpm. Some experiments... 

Immobilized Cells. Cells can be immobilized in the walls of UF hollow fibers and can grow to tissue-like densities (106-107 cells /cm2) between the fibers. This is about 10 times higher than densities achieved in roller bottles the hollow fibers act like natural capillaries in carrying nutrients to the cells and in removing toxic wastes. Cultures can be maintained for months at a time. Products like interferon, monoclonal antibodies, antigens, viruses and hormones may be produced continuously with dramatic increases in yield. In addition, where proteins such as monoclonal antibodies are being produced, subsequent purification steps can be simplified because the product occurs in high concentrations with lower concentrations of serum components than is the case with conventional mouse ascites fluid or suspension culture procedures. 

The rough criteria indicate that if a compound is above a certain level of toxicity, then a compound should be screened. Using a single-culture procedure with non-photosynthetic cells, 3 of 19 known herbicides did not meet the promotion criteria (5). When a two-culture system was used, all herbicides tested would be promoted (4). and Table VII in (1). 

The production of shikonins is an example of both the promise and limitations of current plant cell culture procedures in the area of natureJ products. While productivity at least 10-fold higher than in plants was obtained, this was the result of a systematic but empirical search for the optimal conditions for shikonin accumulation. In many cases it has not been possible to find the culture conditions appropriate for the expression of a secondary metabolic pathway (H, 15). About a dozen examples are known of cell cultures producing a secondary metabolite at levels equal to or higher than in the whole plant (Table I), but with the exception of shikonin none of these systems has commercial use, or is competitive with existing extraction technology. 

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