Theoretically, cultured plant cells are equipped to synthesize the needed biomolecules, vitamins, and other growth elements. However these are supplied in the media for providing maximal/optimal conditions for growth. In general, sucrose in 2–5% concentration is the carbon source. Glucose, fructose, maltose, galactose, mannose, and lactose may also be used. Sucrose plays an important osmotic role in the medium and is required for several metabolic activities.

Amino acids as l-forms play an important role in morphogenesis and serve as sources of reduced nitrogen. Glycine is commonly used and tyrosine supports shoot initiation. Arginine facilitates rooting and amides glutamine and asparigine enhance somatic embryogenesis.

Though plants can synthesize their own vitamins, depending on the nature of plant species and nature of culture, vitamins B₁, B₃, B₆ and myo-ionositol, pantothenic acid, vitamin C, vitamin D and vitamin F have been used in different culture media. B₁ is an important co-factor in carbohydrate metabolism, B₂ improves shoot formation, and prevents explant browning. Vitamin D has a growth-regulatory effect and vitamins C and E act as anti-oxidants. Myo-ionositol, a member of B vitamin complex, is a natural plant constituent and a crucial precursor in biosynthesis of pectin and hemi-cellulose needed for cell wall synthesis. It is also known to support the action of auxins.

Complex nutritive mixtures such as casein hydrolysate (30–300 mg/L), coconut milk (10–20% v/v), yeast extract (50–500 mg/L), tomato juice (30%), and malt extract are added to medium in specific cases to support culture growth.