a conventional medium for the in vitro culture of plants murashige et al physiol plantarum 15 473 479 1962 subsequently explants were transferred to agar plates 8 g l containing regeneration medium ms salts 30 g l sucrose 1 mg l bap i e 6 benzylaminopurine a plant cytokinin 500 mg l of carbenicillin to eliminate bacterial growth and 100 mg l of kanamycin as a selective agent for transgenic plants transformants were selected on the same medium without any hormone incubation was continued until roots had formed copy numbers of specific dnas in transgenic tobacco plants were determined by southern blot analyses total genomic dna was independently isolated from five transgenic plants containing pnb35s gfp aps1 five transgenic plants containing pnb35s aps2 and two transgenic plants containing pnb35s gfp dna isolations were performed using the phytopure plant dna extraction kit from nucleon biosciences according to the manufacturer 39 s instructions following isolations genomic dnas were digested to completion with hindiii and equal quantities were fractionated by agarose gel electrophoresis using standard techniques fractionated dnas were then transferred to hybond n membranes amersham corp and exposed to a 32 p labeled probe specific for the gfp coding region using a southern hybridization protocol known in the art sambrook et.