给你一个EPA的文件做参考，中间有一些审核BT玉米中BT成分的例子

http://www.epa.gov/oppbppd1/biopesticides/pips/bt_brad2/2-id_health.pdf

引用：

Protein Characterization and Expression
The results of the western blot showed the trypsinized extracts of corn lines MON 802, 805, 809, 810, 813, and 814 expressed proteins that comigrated with the Cry1Ab protein as found in MON 801 and the same Cry1Ab protein purified from E. coli. These bands also reacted with antiserum #B6 specific for the tryptic core protein of Cry1Ab. These results indicate the trypsinized proteins found in all these plants were of same molecular size (63 kD) and immunoreactivity with the reference standards of Cry1Ab expressed in E. coli and corn line MON801. CLASSIFICATION: ACCEPTABLE

可能这能让你对BT作物中BT蛋白的测试有个更直观的认识。USDA和EPA对被批准的转基因作物“实质相同”的论断不是轻易做出的，特别是对转入基因的蛋白质表达是很仔细的。绝对不是象你转贴作者说的那样“只检测传统食物中那些已知营养物和反营养物有没有变化”。

至于你举的工业酒精的例子，我没法具体回答，因为我不懂其中的细节。就拿我比较熟悉的说，我对经过严格检验的人工合成的维生素和其他药品完全可以接受，不一定要追求“天然提取”。

我又要举人工选种的例子了，经过自然或诱导基因突变的作物跟转基因技术的确定性比起来怎么样？审核的严格性相比又怎么样呢？