The centers contacted the laboratory for further study and then forwarded the anthrax sample that arrived last week.

It has been confirmed that bentonite was never actually found in the anthrax samples.

The anthrax sample is 40-year-old cow tissue that is not infectious because it has not been processed to produce dangerous spores.

The Army relayed to its headquarters an unconfirmed report that looters may have taken anthrax samples from this sprawling research facility.

In addition, a scientist working at the complex may have buried near it anthrax samples or equipment related to its production.

October 25: Ridge gives an update on the scientific analysis of the anthrax samples.

Although they differ radically, Ridge emphasizes both anthrax samples are from the same Ames strain.

In November 2001, Ross updated the story, reporting that original reports of bentonite in the anthrax samples were incorrect.

What are the health and safety precautions for laboratory workers handling anthrax samples?

So far, all the anthrax samples discovered have characteristics of the so-called Ames strain, a variety the United States used in its germ weapons program.