I am curious about the stability of sugar / sucrose if autoclaved in tissue culture media. As far as I know it should be stable enough to bear the temperature as it melts down at 135 °C without discoloration, and degradation occurs at temperatures of more than 143 °C.
But how is it in media, especially when other components are present?
your concerns are surely justified. Sucrose can be degraded during autoclaving. Hagen et al. (1991) reported that five percent of sucrose was hydrolized after sterilization.
There are also evidences that breakdown products can influence growth behaviour, as showed in the following picture from Stehsel & Caplin (1969):
Best way seems to sterile filtrate sucrose or to autoclave it separately. However, in commercial micropropagation, it adds additional expenses and often not performed. As a general rule, it should be ensured autoclaving times are not excessive. Keeping the procedure parameters constant allows reproducibility and prevents unexpected results.
Hagen, S. R., Muneta, P., Augustin, J., & LeTourneau, D. (1991). Stability and utilization of picloram, vitamins, and sucrose in a tissue culture medium. Plant cell, tissue and organ culture , 25 (1), 45-48.
Stehsel, M. L., & Caplin, S. M. (1969). Sugars: autoclaving vs sterile filtration on the growth of carrot root tissue in culture. Life sciences , 8 (24), 1255-1259.
Thanks for the fast response!!
I already assumed it and will consider it for my projects. I need my cultures to be stable over longer time period as i use tissue culture for conservation of rare plant species. I think break down products of sucrose could cause some additional stress which increases the propability of somaclonal variation.
So i will go safe, sterilize it separately and prepare concentrated sugar stocks. I only have a small lab, doing it for private purposes, so it’s not really necessary to think about work cost