A process for handling an active catalyst includes introducing a mixture of active catalyst particles and a molten organic substance, which is at a temperature T1, and which sets at a lower temperature T2 so that T2<T1, into a mold. As the seed disc rotates, the apertures in the disc rotate along a seed aperture path through a horizontally adjacent seed pool area. The invention also relates to methods for producing a transgenic potato plant and to the transgenic potato plants and parts produced by those methods. The apparatus includes a pressure cap selectably air-tight sealable over the canister. , either by direct contact with the media or indirectly through contact with another intermediate element.