Tissue culture, also known as cell culture, is a technique used in biological research and biotechnology that involves the growth and maintenance of cells or tissues outside of their original organism, typically in a controlled laboratory environment. This technique allows researchers to study cellular processes, develop new therapies, and test the effects of drugs or other compounds on cells under controlled conditions.
Tissue culture usually involves the following steps:
- Tissue or cell isolation: Cells or tissues are first isolated from an organism. This may involve the use of mechanical or enzymatic methods to dissociate cells from the surrounding extracellular matrix and each other. Commonly used enzymes include trypsin and collagenase.
- Plating: The isolated cells are then plated onto a culture dish or flask that is coated with a suitable substrate, such as a layer of extracellular matrix proteins, to promote cell attachment and growth.
- Growth medium: A nutrient-rich liquid medium is added to the culture dish to provide the necessary nutrients, growth factors, and hormones required for cell growth and maintenance. The medium typically contains a mixture of salts, sugars, amino acids, vitamins, and other essential components.
- Incubation: The culture is placed in an incubator that maintains the appropriate temperature, humidity, and gas mixture (usually 5% CO2 and 95% air) to support cell growth. Most mammalian cells are cultured at 37°C (98.6°F), which is close to the body temperature of many animals, including humans.
- Monitoring and subculturing: The cells are regularly monitored for growth, morphology, and viability using a microscope. Once the cells have reached an appropriate density, they are subcultured, a process that involves removing a portion of the cells and transferring them to a new culture dish with fresh medium. This ensures that the cells have enough space and nutrients to continue growing.
There are different types of tissue culture, including:
- Primary culture: Cells are directly isolated from the tissue of an organism and cultured. These cells generally have a limited lifespan in culture and may retain many of the characteristics of the original tissue.
- Cell lines: These are immortalized cells that have been modified, either through genetic manipulation or spontaneous mutation, to grow indefinitely in culture. Cell lines can be derived from primary cultures or established from cancerous tissues.
- Organotypic culture: In this type of culture, tissues are grown in such a way that they maintain some of the original organ’s architecture and function. This can be useful for studying complex tissue interactions and physiological processes in a more physiologically relevant context.
Tissue culture has many applications in research and biotechnology, including drug discovery, gene therapy, regenerative medicine, and the production of recombinant proteins and vaccines.