Establishment of callus culture: Greenhouse grown
plants were used for collection of leaf explants for
establishing callus culture for the production of
andrographolide. About one month old young leaf
was surface sterilized with laboline and then
immersed for 5 min in 0.1% (weight per volume)
HgCl2 solution. Subsequently, they were rinsed three
times with sterile distilled water. For callus induction,
the leaves were aseptically cut into small pieces and
inoculated on Murashige and Skoog [6] medium with
different concentrations of 2,4-D (0.25- 2.0mg/l) and
combination of 2,4 D + Kinitin, 2,4D +NAA and
BAP + NAA. The cultures were incubated under
complete dark condition at 25 ± 1°C