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Cell culture is the process by which either Prokaryotic or Eukaryotic Cell s are grown in a synthetic environment. In practice the term "cell culture" has come to refer to the culturing of cells derived from multicellular eukaryotes, especially Animal cells. Animal cell culture became a routine Laboratory technique in the 1950s, 1 but the concept of maintaining live cell lines separated from their original tissue source was discovered in the 19th Century.2 HISTORY In 1885 Wilhelm Roux removed a portion of the Medulla ry plate of an Embryo nic Chicken and maintained it in a warm Saline Solution for several days, 3 establishing the principle of cell culture. Ross Granville Harrison , working at Johns Hopkins Medical School and then at Yale University , published results of his experiments from 1907-1910, establishing the methodology of Tissue Culture . Schiff, Judith Ann. 4 Yale Alumni Magazine, February 2002. Cell culture techniques were advanced significantly in the 1950s in association with the Polio Pandemic s, op.cit and the Polio Vaccine became one of the first products mass-produced using cell culture techniques. CONCEPTS Culture conditions (for example Growth Media , PH , Temperature ) vary widely for each cell type, and variation of conditions for a particular cell type can result in different Phenotype s being expressed. This article is concerned with modern culture methods. At present, this article is biased toward the culture of mammalian cells. A cell line is grown and maintained in the favourable conditions (e.g. 37 °C , 5% CO2 ) in a Cell Incubator . All cell lines originate from cell cultures with a limited lifetime, but occasionally some cells keep on multiplying because they mutated. These cells can be cultured infinitely. Sometimes, it is possible to fuse normal cells with an immortal cell line. An example is the way s isolated from the blood of an Immunised animal are combined with Hybridoma cell lines in a Selective Growth Medium : only the fused cells survive. Cell culture methods can be applied to either s, such as bacteria or eukarytotic microorganisms, or to cells removed from a multi-cellular tissue. Related to cell culture are Tissue Culture and Organ Culture , which refer to methods for growing pieces of tissue or entire organs removed from an organism in an artificial environment. "Tissue culture" has lost much of its original meaning in that it is now used generically for cell culture of mammalian cells or more broadly any cell type removed from a multicellular organism; however, when used without a qualifier it is usually interpreted as meaning mammalian cell culture. Ultimately, all cell culture applied to cells from multicellular organisms starts with the removal of cells from a tissue, which is likely where the blurring of the distinction between "tissue culture" and "cell culture" derives. The culture of Viruses requires the culture of cells as hosts for the growth and replication of the virus. Cells can be cultured for a longer time if they are split regularly. Growth medium is then replaced and the cells are diluted (after first detaching them by Trypsin of NaOH from the support). The key to success in culturing cells is to mimic the environment in which they found themselves before being transplanted to an artificial environment. This environment is often an Extracellular Fluid derived from Blood . Ham's Tissue Culture Medium , a commonly used medium for mammalian cells, is an attempt to recreate this extracellular fluid. Some cells naturally live without attaching to a surface, such as cells that exist in the bloodstream. Others require a surface, such as most cells derived from solid tissues. Still others can live under either condition and exhibit different phenotypes depending on whether or not they are attached to a surface, such as yeast and many types of bacteria. Also, the substrate might or might not provide nutrients to the cells. In the case of most cells derived from tissues, nutrients are provided by a liquid broth that bathes cells attached to a surface. There are cells that require an "air-liquid interface" to grow properly; in this case the cells are often grown on a "raft" of organic material that floats on the surface of a nutrient broth and acts like a wet sponge, feeding the cells from underneath while their tops are exposed to the air. For bacteria and yeast, small quantities of cells are usually grown on a solid support that contains nutrients embedded in it, something like stiff nutritious Jello , while large-scale cultures are grown with the cells suspended in a Nutrient Broth . Cell lines that originate with Human s are somewhat controversial in Bioethics , as they may easily outlive their parent organism and lead to the discovery of lucrative medical treatments. In the pioneering decision in this area, the Supreme Court Of California held in 1990 that human patients have no property rights in cell lines derived from organs removed with their consent. ceb It is estimated that about 20% of human cell lines are not the kind of cells they are generally assumed to be (MacLeoud ''et al''. 1999). The reason for this is that some cell lines exhibit vigorous growth and thus cross-contaminate cultures of other cell lines, in time overgrowing and displacing the original cells. The most common contaminant is the HeLa cell line. While this may not be of significance when general properties such as Cell Metabolism are researched, it is highly relevant e.g. in medical research focusing on a specific type of cell. Results of such research will be at least flawed, if not outright wrong in their conclusion, with possible consequences if therapeutic approaches are developed based on it. (Masters 2002). See List Of Contaminated Cell Lines . APPLICATIONS Mass culturing of live cell lines allows the production of biological compounds manufactured by these cells, including Enzymes , Hormones , Vaccines , Immunobiologicals ( Monoclonal Antibodies , Interleukins and Lymphokines ), Anticancer Agents , etc. Vaccines Vaccine s for Polio , Measles , Mumps , Rubella , and Chickenpox are currently made by cell culture. Due to the H5N1 Pandemic threat, research into using cell culture for Flu Vaccine s is being funded by the United States government in areas as diverse as using the common cold as a vector and use of Adjuvant s. cold as vector news cold as vector research abstract adjuvant EXAMPLES
; Primate cell lines
; Rat tumor cell lines
; Mouse cell lines
;Plant cell lines
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