VPB 321: Animal Biotechnology (2+1)

CELL CULTURE AND CELL LINES

• Tissue culture: The term tissue culture is used as the generic term to include organ culture and cell culture
• Cell culture is the in vitro propagation of cells harvested from animal organs or tissues.
• Organ culture involves the maintenance of whole organ or parts of an organ in a way that may allow differentiation and preservation of the architecture and/or function. In primary explant culture, fragments of tissues are placed at a glass-liquid interface, where following attachment, migration is promoted in the plane of the solid surface.
• Cell culture involves the growth and maintenance of individual cell types in vitro.
• In vivo , the vascular system provides cells with nutrients and growth factors and also with a means of removing metabolic byproducts. This maintains the viability of the cells. The extracellular environment is also necessary for in vitro culture systems .
• Nutrients are provided by the culture medium which may also provide a stable pH and a defined salt concentration. Chemically defined media were developed to replace the biological fluids and it has the advantages of consistency between batches of media, ease of sterilization and reduced chance of microbial contamination. It is usually necessary to add serum to provide growth factors.
• Media formulations used include a complex mixture of carbohydrates, amino acids, salts, vitamins,hormones and growth factors. The salt concentration is isotonic to prevent osmotic imbalances. Bicarbonate is often included to act as a buffer system is conjunction with the carbon-di-oxide enriched environment (5-10% Co2/ 95% air) in which the cells are cultured. This allows the cultures to be maintained around the optimal pH for growth of about 7.4.
• For most cultures, the addition of serum to the medium (5- 10% V/V) is required to maintain cell growth. The sera used mostly in tissue culture are calf, fetal, bovine,horse and human. Calf serum is the most widely used Fetal bovine second. Antibiotics such as penicillin and streptomycin are added to reduce the bacterial or fungal contamination of the cell culture.