Effect of Method of Agar Addition on Post-autoclave pH of the Tissue Culture Media

Tissue culture media (MS, GB-5 and N6) were gelled with agarby employing different methods When agar was dissolved directlyin media by autoclaving at 120 °C for 1 mm followed by sterilization,the media pH dropped markedly — more so at the lower concentrationsof agar On the other hand, when agar was first dissolved indistilled water and added to the culture media the pH loss wasminimized considerably pH measurements carried out as a functionof time showed a gradual decline in media pH The media supplementedwith Panax ginseng callus became more acidic than the mediawith no callus Tentative reasons for the post autoclave pH fallassociated with various methods of agar addition are described Culture media, agar addition, post-autoclave pH, Panax gingseng