What culture media provide
Explants lack roots for water uptake and leaves for photosynthesis initially. Media supplies minerals (MS basal salts), carbon (sucrose), vitamins, and growth regulators (auxin, cytokinin).
Murashige & Skoog (MS) medium
Industry standard for many species. Macronutrients (N, P, K, Ca, Mg, S) and micronutrients (Fe, Mn, Zn, etc.) at defined concentrations.
Growth regulator balance
- High auxin / low cytokinin — favors root development.
- High cytokinin / low auxin — promotes shoot proliferation.
- Equal ratios — may induce callus (undifferentiated mass).
pH and autoclaving
Adjust to pH 5.6–5.8 before autoclaving at 121°C for 15–20 minutes. Heat-labile components (some vitamins, hormones) are added after autoclaving from filter-sterilized stock solutions.