It is advisable to add one or two control seeds from a known transformed plant onto a marked location on at least a few of the selection plates. Sterilize these seed also. Dry plates in laminar flow hood until seed no longer flows when plate is tipped. Use one ml agarose for every 500-1000 seed. Plate 2000 to 4000 seed per 150 x 15 mm plate.
Higher densities can make antibiotic selection less effective.
Vernalize plates for two nights in cold room. Move plates to growth chamber. After about 7 days, transformants should be clearly identifiable as dark green plants with healthy green secondary leaves and roots that extend over and into the selective medium. Transplant plantlets to soil, grow, and collect seed. If you break the root, put plantlet onto a new selection plate for a few days before transplanting.