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Cell Culture

The maintenance and growth of the cells of multi-cellular organisms outside the body in specially designed containers and under precise conditions of temperature, humidity, nutrition, and freedom from contamination.

In a broad sense, cells, tissues, and organs that are isolated and maintained in the laboratory are considered the objects of tissue culture.

The techniques of cell culture have allowed scientists to use cultures of cells for experimental studies and for biological assays of many types.

Cell culture is the process by which prokaryotic or eukaryotic are grown under controlled conditions.

Cell culture techniques were advanced significantly in the 1940s and 1950s to support research in virology. Growing viruses in cell cultures allowed the preparation of purified viruses for the manufacture of vaccines.

The Salk polio vaccine was one of the first products mass-produced using cell culture techniques.

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 system 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.

Cell culture is a fundamental component of tissue culture and tissue engineering, as it establishes the basics of growing and maintaining cells ex vivo.

Vaccines for polio, measles, mumps, rubella, and chickenpox are currently made in cell cultures. Due to the H5N1 pandemic threat, research into using cell culture for influenza vaccines is being funded by the governments. Novel ideas in the field include recombinant DNA-based vaccines, such as one made using human adenovirus (a common cold virus) as a vector, or the use of adjuvants.

Tissue Culture


It is a method of biological research in which fragments of tissue from an animal or plant are transferred to an artificial environment in which they can continue to survive and function.

The cultured tissue may consist of a single cell, a population of cells, or a whole or part of an organ. Cells in culture may multiply; change size, form, or function; exhibit specialized activity (muscle cells, for example, may contract); or interact with other cells.

Tissue culture permits control of the cellular environment, allowing the behavior of cells to be both examined and manipulated.

Tissue cultures have revealed basic information about cells regarding their composition and form; their biochemical, genetic, and reproductive activity; their nutrition, metabolism, specialized functions, and processes of aging and healing; the effects on cells of physical, chemical, and biological agents (drugs and viruses, for example); and the differences between normal cells and abnormal cells such as cancers.

Working with tissue cultures has helped to identify infections, enzyme deficiencies, and chromosomal abnormalities, to classify brain tumors, and to formulate and test drugs and vaccines.

Tissue culture techniques have been used to cull many kinds of hybrid cells that contain chromosomes from different species in the same cell, allowing the functions of individual chromosomes to be separately defined. Tissue-culture studies have clarified the genetic causes of certain hereditary diseases, and methods have been developed for detecting environmental substances that may cause gene damage.

The nature of certain cancers has been elucidated by the discovery of specific genes and chromosomal aberrations that are associated with the disease. Studies of cell cultures have revealed the existence of a so-called cytoskeleton in mammalian cells, which gives the cell its shape and regulates a variety of biochemical activities.

The methods of somatic cell genetics are being applied to plant cells in an effort to develop new straw of cereal crops with improved nutritional properties.

Bioreactor and Bioprocessing


A bioreactor is a vessel in which is carried out a chemical process that involves organisms or biochemically active substances derived from such organisms. Bioreactor design is quite a complex engineering task.

Under optimum conditions, the microorganisms or cells will reproduce at an astounding rate. The vessel’s environmental conditions like gas (i.e., air, oxygen, nitrogen, carbon dioxide) flow rates, temperature, ph and dissolved oxygen levels, and agitation speed need to be closely monitored and controlled.

NASA has developed a new type of oil bioreactor that artificially grows tissue in cell cultures. NASA’s tissue bioreactor can grow heart tissue, skeletal tissue, ligaments, cancer tissue for study, and other types of tissue.

Bioreactors are also used to produce energy from waste and other biological sources.

Biofuels can be produced from plans through a reactor

Bioreactors are also designed to treat sewage and wastewater

In the most efficient of these systems, there is a supply of free-flowing, chemically inert media that acts as a receptacle for the bacteria that breaks down the raw sewage.

Examples of these bioreactors often have separate, sequential tanks and a mechanical separator or cyclone to speed the division of water and biosolids.

In bioreactors where the goal is to grow cells or tissues for experimental or therapeutic purposes, the design is significantly different from industrial bioreactors. Many cells and tissues, especially mammalian ones, must have a surface or other structural support in order to grow, and agitated environments are often destructive to these cell types and tissues. Higher organisms also need a more complex growth medium.

Bioprocessing: Bioprocessing is the use of biological materials (organisms, cells, organelles, enzymes) to carry out a process for commercial, medical, or scientific reasons.

Some industries have a long tradition of enzyme use:

v   In leather tanning, hides are softened and hair removed using the proteases in feces.

v   In brewing, amylases in germinating barley are used to convert starch to maltose

v   Maltose is then used by yeast for growth and ethanol production.

v   In cheese making proteins in milk is coagulated, using rennin from calf stomachs.

v   Glucose Isomerase: production of fructose from glucose (sweeter – use in confection

v   Sucrase: production of glucose and fructose sucrose (as above).

v   Glucose oxidase: used in the detection of glucose blood/urine by diabetics

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