Animal cell culture
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The process of culture of animal cells in an environment outside the tissue (ex vivo) from which it is obtained is called Animal Cell Culture (ACC). The process of ACC is carried out under strict laboratory conditions of asepsis, sterility and controlled environment involving temperature, gases and pressure. It should mimic the in vivo environment successfully such that the cells are capable of survival and proliferation in a controlled manner.
Culturable cells
Theoretically, cells of any type can be cultured upon procurement in a viable state from any organ or tissue. However, not all types of cells are capable of survival in such an artificial environment because of many reasons on which the artificial environment may fail to mimic the biochemical parameters of the source environment. Some good examples include the absence of growth regulators, cell to cell signal molecules…etc. Under optimal conditions of maintenance, the cell culture established can be sub-cultured (passaging) until a pure-culture of specific cell type is obtained. This can repeatedly sub-cultured to maintain as a cell-line. As a matter of fact, cell lines from cancerous tissues have also been established. The presence of excess growth regulators or other factors may often render the cells to undergo rapid uncontrolled proliferation resulting in a cancerous state. Good examples of established cell lines are HeLa, BHK, Vero, [[CHO] etc
Media
The artificial environment is generally known as media. A media comprises an appropriate source of energy for the cells which they can easily utilize and compounds which regulate the cell cycle. A typical media may or may-not comprise of serum. The latter is called a serum-free media. Some of the common sources of serum can be fetal bovine serum, equine serum, calf serum etc. both the types of media have their own set of advantages and disadvantages.
Applications
Consider drug testing in the process of discovery of a new drug. The test drug has got to pass through many phases after which it gets approved and marketed. Among the preliminary phases, one such involves the testing of the test drug on animals for toxicity and/or efficacy and efficiency. Now this can also be harmful and/or fatal to the animal on which it is being tested. This can be minimized if the drug is tested on a cell line it is targeted against as a cure, thereby assessing the toxicity on an initial scale thus reducing the probability of death on the test animal.
Production of therapeutically significant biological compounds like hormones and proteins on an industrial scale have be made simpler, faster and more efficient by the use of cell lines in the place of the living animal themselves.
Vaccines effective against many viral infections and diseases require the cultivation and mass production of the virus followed by its attenuation. The drawback in this is that virus requires a living medium to replicate and multiply. Rather than the traditional concept- “Sacrifice one life to save many”, ACC can be employed to mass produce the virus. Passively, ACC can be employed to reduce the virulence of particular virus strains by cultivating them on cells other than target cells which the virus infects followed by repeated passaging.
Studies on regenerative medicine can be understood on deeper concepts if ACC is fully exploited as cells behave in a spectrum of patterns under various environments which can be simulated in an ACC laboratory and followed in vitro.
Active research on stem cell culture, proliferation leading to organogenesis is at a slow phase due to the non-availability of research materials. This can however be overcome if ACC is fully utilized. The fruits of such a study can be more than overwhelming towards the betterment of human life.
ACC also finds application in the preservation of highly valuable cord blood cells which are nothing but stem cells specific to an individual.
ACC is a potential tool in Assisted Conception which requires the maintenance of sperms and the egg from the donors viable under laboratory conditions after which they are allowed to fertilize (in vitro) followed by re-implantation.
History
1880 AD- Arnold showed that leucocytes can divide outside the body
1903 AD- Jolly studied the behavior of animal tissue explants immersed in serum, lymph, or ascites fluid.
1907 AD- Harrison cultured frog tadpole spinal chord in a lymph drop hanging from a cover slip of a cavity slide.
1913 AD- Carrel developed a complicated methodology for maintaining cultures free of contamination
References
Vidya Sagar. K, International Conference on Alleviation Of Malnutrition and Betterment of Human Health, Purdue University, March 2005.