Organic compounds are added in large quantities to culture media.
Sugars: Sugars serve as an energy source for plant culture. Sucrose is the most commonly used sugar in plant culture media, although glucose, fructose and sorbitol are also used in some medium formulas. Sucrose is partially broken down into fructose and glucose during autoclaving . Sucrose also acts as an osmoticum in the medium. Generally 20-40 gram sucrose is added in each liter of liquid medium. Starches are also used in some medium formulas both as the support substance and energy source.
Vitamins: Vitamins can improve, but are not absolutely necessary for plant growth in culture. Off all vitamins, only thiamin (B1) is considered to be essential for many plant species in culture. It is required for carbohydrate metabolism and the biosynthesis of some amino acids. Nicotinic acid (niacin) and pyridoxine (B6), biotin, folic acid, ascorbic acid (vitamin C) and tocopherol (vitamin E) are also used in some media.
Myo-inositol: Myo-inositol is a sugar alcohol and is thought to be important in membrane and cell wall development. It is usually added to media for monocots as well as some dicots and gymnosperms.
Complex organic Compounds: Complex organic compounds such as coconut milk or juice, yeast extract, fruit juices and fruit pulps are used in some medium formulas. It is not known exactly what components in these organic supplements is responsible for the improved growth of the culture.