Last year Dr. Read's team analyzed an anthrax sample taken from Robert Stevens, a photo editor who died after contracting anthrax from a letter sent to the American Media building in Boca Raton, Fla.
So far, investigators have photographed the outside of the envelope, but have not yet opened the letter or analyzed the anthrax spores.
Instead of being sent to the C.D.C., the agency analyzing anthrax samples from Florida and New York, the letter was sent by the Capitol police to the Army's biological laboratory at Fort Detrick, Md. As postal workers began falling sick this week, tensions erupted between these two agencies as well as with the F.B.I., which was supposed to be sharing information each laboratory was producing.
Dr. Ivins, for instance, was asked to analyze the anthrax envelope that was sent to Mr. Daschle's office on Oct. 9, 2001.
That theory of a biodefense insider placed many scientists at the infectious diseases institute and other laboratories under scrutiny, even as they helped the F.B.I. analyze the anthrax powder in the letters.
FBI scientists and outside experts hired by the bureau to analyze the anthrax recovered from the mailings announced Aug. 18 that although they had found silicon, it occurred within the spores naturally and was not added.
Specimens from those two centers were gathered Sunday and are being analyzed for possible anthrax contamination from the Princeton mailbox.
To further investigate the underlining mechanism, here we analyzed photocatalyst-mediated inactivation of anthrax lethal toxin (LT) and the survival rate of spore after the macrophage clearance in vitro.
Fourteen of the 26 clinical specimens analyzed from seven patients with laboratory-confirmed anthrax were positive in both the CW- and CAP-DFA assays (Table 3).
BioWatch uses vacuum-powered samplers that suck air through composite filters, which are removed daily and analyzed at public health labs for signs of anthrax, smallpox, plague or other deadly pathogens.
