Tissue Culture

Tissue culture is the process by which tissues are obtained from an organism and are made to grow in a separate environment. Culture is performed on a medium that may be solid, semi-solid, or liquid, such as agar and broth. The general term “tissue culture” usually pertains to culture of animal cells. For plant cells, the term “plant tissue culture” is being used.

Cell Culture

Cell culture is a process by which cells are made to grow outside their original milieu. They are usually kept inside an incubator. Cells are initially obtained from plant or animal tissues, grown in a medium supplied with appropriate nutrients in a controlled condition. These cells are placed in special containers. External factors such as temperature and humidity are calculated, and the culture has to be made to be contaminant free. Tissue cultures are presently being done left and right, but the reality is that this process has long been in existence. The first documented cell culture was performed in the 1950’s, which saw the birth of the world’s first engineered tadpole.

Cells are usually incubated in glass containers. In vitro is a term used to denote growth outside the organism. Culture naturally begins with a solitary cell that eventually thrives, increases in size, divides, replicates, and this cycle is repeated until the particular element in question is not detected.

Usually, there is one type of cell that is being cultivated in a single culture batch. However, mixed cultures are being used in some fields such as wastewater treatment and food science. Cells that look alike in terms of structure are described as homogenous, and are called clones, as they are derived from one parent cell. The cell population becomes heterogenous once there are variations in the genetic makeup of the cells that comprise the batch.

Cell culture is done by scientists mainly to study cell biochemistry, although its other applications in research include the study of cell metabolism, toxicology (i.e., drug effects), and behavior of cancer cells and the subsequent treatment. In recent times, the term “tissue engineering” has come into usage and this is the technology that is used in creating artificial skin.

Working on large and numerous cultures enable scientists and researchers to work on studies that can determine what viruses or proteins are necessary for an animal’s survival and what organisms are actually harmful. Cell cultures produce a constant, homogenous sample, making this process extremely useful in researches. The usual problem with cell cultures, though, is the propensity towards the production of mutant cells. Another drawback is that some cells undergo senescence, which is a term for advanced aging. Advanced aging would set in at times after a specific number of cycles of cell division. When senescence sets in, the cells simply cease to replicate, and die following the breakdown of the DNA material.

Cell culture has yet to find widespread commercial use. To illustrate this, researchers have been in a constant quest of a plant product that can be produced by harvesting cells and carrying out a process called bioprospecting. This will entail going through approximately 10,000 species of plants and cultivating a multitude of cell cultures.

Historical usage

The first reported attempt to culture tissues was in 1885, when Wilhelm Roux harvested portions of the medullary plate from a chicken embryo. The tissue was kept in a temperature-controlled saline solution for days.

Ross Granville Harrison, a zoologist initially connected with the Johns Hopkins Medical School and subsequently transferred to Yale, was able to promote the growth of the nerve processes of a nerve cell of a frog. The cells were kept in clotted lymph medium. Harrison performed a series of similar experiment from 1907 to 1910 and published his results, thus laying the basic groundwork for the methodology involved in tissue culture.

E. Steinhardt, C. Israeli, and R. A. Lambert did similar experiments by producing vaccinia virus in the corneal tissue of guinea pigs in 1913.

Sydney Ringer, an English physiologist in the 19th century, formulated saline solutions. These solutions contained measured amounts of electrolytes such as sodium, potassium, magnesium, and calcium, which are all necessary to sustain the pumping of an animal heart in vitro, or outside the organism’s body.

The 1940s and the 1950s saw the immense advancement in culture techniques, mainly to provide sufficient material in the study of viruses. The study of virology necessitated the use of cell cultures so that viruses can be isolated and vaccines can be tested. Jonas Sak came up with the injectable polio vaccine, which is one of the first products of cell culture to be manufactured on a large-scale basis. The vaccine was produced by the cell culture studies of John Franklin Enders, Thomas Huckle Weller, and Frederick Chapman Robbins. Together they developed a way of producing the virus by using the kidney cells of monkeys, and because of their groundbreaking studies, they were awarded the Nobel Prize.

Plant Tissue Culture

The process by which plant cells are harvested and made to propagate under specified conditions into clones is called plant tissue culture. To date, various techniques in plant tissue have already explored, providing a good number of advantages as opposed to the traditional method. They include the following:

-The more advanced techniques enables the production of exact replica of plants that have good traits (i.e.. good fruits, flowers, plant resilience)

-Plants mature faster.

-Plants may be produced even without seeds, pollinators, and other agents that are required in traditional plant fertilization.

-The entire plant structure can be reproduced from genetically modified plant cells. The plants can be produced in containers that can be transferred with less risk of exposure to diseases, contaminants, pests, and other pathogens.

-Plants that are difficult to cultivate from seeds, such as nepenthes and orchids, can now be easily raised using plant tissue culture.

-Plant varieties can be “cleaned” of viruses and other pathogens using plant tissue culture. The “cleaned stock” can then be replicated for agricultural and horticultural use.

-The principle with which plant tissue culture operates is that most plant cells can regenerate an entire plant. This characteristic is known as totipotency. As such, plant cell culture is very useful in cultivating single cells, those not equipped with cell walls such as protoplasts, torn pieces of plant structures such as remnants of leaves and roots. With the proper hormones and nutrients, plants can actually be recreated.