In biology, the terms cell culture and tissue culture are often used interchangeably. Both involve removing cells, tissues or organs from animals or plants so that they can then be grown on culture media under sterile and controlled conditions. However, there are some notable differences. For example, the time required to culture cells and tissues varies. Cells can be cultured for as little as 1 day to as long as several weeks, depending on the cell type (i.e. neurons can be cultured for 3 to 6 weeks). Tissue culture times are significantly longer, with plant tissue cultures up to 14 weeks or more propagated. Another difference is that some cell lines are "immortal" (such as HeLa cells), meaning they can divide indefinitely in cell culture as long as the proper conditions are met.
Furthermore, different culture requirements and experimental conditions depending on the sample type—medium type, supplementary nutrients, humidity, osmolarity, cell density, incubation time, temperature, etc.—need to be carefully optimized.
How does cell culture work
Cell culture involves culturing cells, whether in suspension or adherent (monolayer) culture, in a medium selected specifically for the cell type of choice. Typically, the medium will contain compounds such as amino acids, glucose, vitamins, inorganic salts, and lipids. They may also contain animal serum, growth factors, hormones, antibiotics and antioxidants. Several types of media are available, including serum-based, serum-free, animal-free, protein-free, and chemically defined options that can be supplemented with other components, such as calf serum. The cells are then grown in an incubator to ensure optimal cell growth conditions - such as temperature, oxygen and carbon dioxide levels - are maintained.
Cultured cells require a constant supply of nutrients for healthy growth, so the medium must be replenished regularly. Additionally, adherent cell lines require subculture once they reach confluence (the point at which the available surface area is completely covered) for continued growth. During media exchange and subculturing, it is critical to protect the cultures from any chemical or biological contamination.
What is cell culture good for?
Cell culture has many applications in research, bioproduction and diagnostics. Animal, plant, and bacterial cell cultures are routinely used to study biological processes and genetics, and to produce bio-derived molecules, including vaccines, proteins, enzymes, antibodies, and hormones. For example, in drug discovery and development, mammalian cell cultures provide models for disease research, allowing target identification and validation. They are also used in cell-based high-throughput screening assays to test the efficacy and safety of potential new drugs. In clinical settings, cell culture techniques are routinely used to identify the organism causing an infectious disease and identify the most effective antimicrobial agent to treat it.
Why use cell culture technology?
Cell culture technology is an extremely important tool in cell and molecular biology. They provide researchers with excellent model systems for studying the normal physiology and biochemistry of cells, the effects of drugs and toxic compounds, and mutagenesis and carcinogenesis.
Following are the different types of tissue culture techniques:
In this culture, the explants are obtained from an in-vitro derived plant and introduced into a laboratory where they proliferate. The explant should be sterilized to prevent it from tissue damage.
This involves the in-vitro development of an embryo. For this, an embryo is isolated from a living organism. Both, a mature or an immature embryo can be used in the process. Mature embryos can be obtained from ripe seeds. The immature embryos are obtained from the seeds that failed to germinate. The ovule, seed or fruit is already sterilized, therefore, it does not need to be sterilized again.
A callus is an unorganized, dividing mass of cells. When the explants are cultured in a proper medium, the callus is obtained. The growth of callus is followed by organ differentiation. The culture is grown on a gel-like medium composed of agar and specific nutrients required for the growth of the cells.
In this, any organ of the plant such as shoot, leaf, can be used as an explant. A number of methods can be used for the organ culture, such as plasma clot method, raft method, grid method, and agar gel method. This method is used to preserve the structure and functions of an organism.
It is a cell without a cell wall. A protoplast can be cultured using the hanging-drop method, or micro-culture chambers. In protoplast culture, a number of phases can be observed: development of cell wall, cell division, regeneration of a whole plant.