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Tissue culture is the growth of tissues and/or cells separate from the organism. This is typically facilitated via use of a liquid, semi-solid, or solid growth medium, such as broth or agar. Tissue culture commonly refers to the culture of animal cells and tissues, while the more specific term plant tissue culture is being named for the plants.
In modern usage, "tissue culture" generally refers to the growth of eukaryotic cells in vitro. It is often used interchangeably with cell culture to specifically describe the in vitro culturing of sperm donor cells.
It is a tool for the study of animal cell biology in vitro model of cell growth to allow a highly selective environment which is easily manipulated (used to optimize cell signaling pathways).
Cell culture is the complex process by which cells are grown under controlled conditions. In practice, the term "cell culture" has come to refer to the culturing of cells derived from multicellular eukaryotes, especially animal cells. However, there are also cultures of plants, fungi and microbes, including viruses, bacteria and protists. The historical development and methods of cell culture are closely interrelated to those of tissue culture and organ culture.
Animal cell culture became a common laboratory technique in the mid-1900s, but the concept of maintaining live cell lines separated from their original tissue source was discovered in the 19th century.
The 19th-century English physiologist Sydney Ringer developed salt solutions containing the chlorides of sodium, potassium, calcium and magnesium suitable for maintaining the beating of an isolated animal heart outside of the body.[http://www.whonamedit.com/synd.cfm/2119.html] In 1885 Wilhelm Roux removed a portion of the medullary plate of an embryonic chicken and maintained it in a warm saline solution for several days, establishing the principle of tissue culture. Ross Granville Harrison, working at Johns Hopkins Medical School and then at Yale University, published results of his experiments from 1907â€“1910, establishing the methodology of tissue culture.
Cell culture techniques were advanced significantly in the 1940s and 1950s to support research in virology. Growing viruses in cell cultures allowed preparation of purified viruses for the manufacture of vaccines. The injectable polio vaccine developed by Jonas Salk was one of the first products mass-produced using cell culture techniques. This vaccine was made possible by the cell culture research of John Franklin Enders, Thomas Huckle Weller, and Frederick Chapman Robbins, who were awarded a Nobel Prize for their discovery of a method of growing the virus in monkey kidney cell cultures.
Concepts in mammalian cell culture
Isolation of cells
Cells can be isolated from tissues for ex vivoculture in several ways. Cells can be easily purified from blood, however only thewhite cells are capable of growth in culture. Mononuclear cells can be released from soft tissues by enzymatic digestion with enzymes such as collagenase, trypsin, or pronase, which break down the extracellular matrix. Alternatively, pieces of tissue can be placed in growth media, and the cells that grow out are available for culture. This method is known as explant culture.
Cells that are cultured directly from a subject are known as primary cells. With the exception of some derived from tumors, most primary cell cultures have limited lifespan. After a certain number of population doublings (called the Hayflick limit) cells undergo the process of senescence and stop dividing, while generally retaining viability.
An established or immortalisedcell line has acquired the ability to proliferate indefinitely either through random mutation or deliberate modification, such as artificial expression of the telomerasegene. There are numerous well established cell lines representative of particular cell types.
Maintaining cells in culture
Cells are grown and maintained at an appropriate temperature and gas mixture (typically, 37Â°C, 5% CO2 for mammalian cells) in a cell incubator. Culture conditions vary widely for each cell type, and variation of conditions for a particular cell type can result in different phenotypes being expressed.
Aside from temperature and gas mixture, the most commonly varied factor in culture systems is the growth medium. Recipes for growth media can vary in pH, glucose concentration, growth factors, and the presence of other nutrients. The growth factors used to supplement media are often derived from animal blood, such as calf serum. One complication of these blood-derived ingred
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Answers:You are using confusing terms. Tissue culture is a method where cells grown in "test tubes" in a liquid nutrient media. Tissue culture removes the individual cells from the effects of being a part of an organ or exogenous chemical signals like hormones. Is this what you mean or do you mean a Tissue SAMPLE? How you collect tissue samples depends on what you intend to do with the virus. You can collect cells which contain both whole virus and it component parts that are being assembled, or you can collect the liquid around the cells to get whole live virus. Sometimes there are no cells left as the virus destroys the cells at maturity. If you are doing PCR on the whole virus, you could even just place a very small piece of filter paper on the tissue sample and pcr that tiny piece of paper.
Answers:When you grow a plant from a cutting, you just cut a piece from the parent plant and put it in soil (maybe dipping it in a rooting powder first). For succulents, the cut end should be allowed to dry and harden first. Maybe you've done this yourself with a spider plant or Christmas cactus. For plant tissue culture, a scientist or plant propagator only removes a few cells from the meristem of a plant. The meristem (or meristematic tissue) is an area where the cells haven't differentiated into specialized cells (root, leaf, flower, etc.) yet, so these cells have the potential to grow into any type of cell in the plant. They're also too young to have been infected by viruses, so they can be used to produce disease-free plants. The cells are placed on a nutrient agar and sealed so the cells can grow into baby plants in a disease-free environment. This is the best way to produce a lot of plants that are identical to the parent plant the cells were taken from (they're clones of the plant that donated the cells) in a short period of time. Orchids were one of the first plants to be produced this way, but now there are lots more.
Answers:1. F 2. B 3. A 4. C 5. E
Answers:Are you sure you copied the two questions down correctly? They ask essentially the same thing, the only difference between the two is that (1) refers to 'small masses of neuron cell bodies' and (2) refers to 'collections of nerve cell bodies', with both entities being outside of the CNS. The name given to a collection of neuronal cell bodies outside the CNS is ganglia, like the dorsal root ganglia which are found at each spinal segment just outside of the spinal cord, and autonomic ganglia. If one of the question actually referred to a collection of neuronal cell bodies *inside* the CNS, then the name is usually nuclei.