She has concluded that 15 institutions worked recently with the Ames strain.

The Ames strain came to wide public attention in association with the 2001 anthrax attacks.

Investigators persisted, even though Iowa state officials said they could find no evidence of the Ames strain.

In May 1986, his vaccine study and the Ames strain made their public debut.

Some 15 laboratories are known to possess or have worked with the Ames strain.

Those analyses yielded evidence of the Ames strain in some samples.

The Ames strain is now used in labs around the world.

Both are the Ames strain, which federal officials have identified as the particularly virulent type of anthrax used in the recent attacks.

There was no specific mention or particular denial of the use of the Ames strain.

Iraq has tried to obtain the Ames strain, officials say, but has never succeeded.