Induction of Callus

Callus induction is usually the first visible milestone in a tissue culture experiment. A small, sterile segment of explant - typically 1 to 2 cm, taken from a leaf, stem, tuber or root - is inoculated, meaning it is transferred into a sterile glass tube containing nutrient medium. For callus induction the medium used is MS nutrient medium supplemented with auxins, and the inoculated explant is incubated at 25 degC +/- 2 degC under an alternating light and dark period of 12 hours each. Under these conditions cell division is induced, and before long the upper surface of the explant develops into a visible mass of callus - the unorganized growth of plant cells or tissue that is the defining feature of a dedifferen …