Callus will start to become visible after about 7 days post initiation. Friable type II callus should be visually selected under a stereoscope at each subsequent transfer to maintain an optimal phenotype. Callus should be transferred to fresh medium at 2-4 week intervals depending on growth rate. Wrap plates with Parafilm. Carefully wash gelrite off of roots with room temperature water.
Place transplants into peat pots.
Move plants to growth chamber or greenhouse. Water well and cover plants in peat pots with 1-2 layers of cheese cloth to shade and reduce water loss. Remove cheese cloth after 2-3 days. Transplant plants in peat pots into large pots or directly into the field as soon as roots are seen growing through the peat pot. Structure and function of selectable and non-selectable transgenes in maize after introduction by particle bombardment.