Last fall, at a business lunch with co-workers, Grace Booth enjoyed three chicken enchiladas. The food, she recalls, was very good - but then something went very wrong. I thought, oh my God, what is happening to me? I felt like I was going to die." In the emergency room in nearby Oakland the diagnosis was severe allergic reaction and from here Grace Booth's story reached officials in Washington. At the time the national corn market was in an uproar. Starlink, a gene modified corn not approved for human food, had been found in taco shells and recalls were emptying the shelves of corn products. The fear was possible allergic reactions. At that moment, Booth says, she had no idea that the corn tortillas in her lunch were about to be recalled. In the wake of the recalls more than 50 Americans, including Booth, claimed they had reactions to Starlink corn. That forced the government to launch the first full-scale allergy investigation in the history of biotech food. It has taken months, but the Centers for Disease Control and the Food and Drug Administration have collected food samples and blood from two dozen people whose cases were believed most serious. [Symptoms] "[v]aried from just abdominal pain and diarrhea [or] skin rashes to some patients ... having very severe life-threatening reactions," said Dr. Marc Rothenberg, the allergy chief at Cincinnati Children's Hospital. He is an adviser to the government in the Starlink investigation. Its slow going he says because investigators first had to find the Starlink protein and then invent a blood test.