Method for producing cell cultures of the family betulaceae, compositions comprising said cell cultures and use of said cell cultures

The present invention relates to a method for producing a cell culture of a plant of the family Betulaceae, said method comprising two stages, where in the first stage birch callus line is cultured in a liquid medium comprising a medium used for plant cell and tissue culture, with or without irradiation, to obtain primary suspension cell culture, and in the second stage the primary suspension cell culture is up-scaled in at least two steps in the liquid medium with or without irradiation.