"Initially, scanning electron microscopy [SEM] conducted at another laboratory, showed high silicon and oxygen signals that led them to conclude that the spores were a weaponized form, says Kotula. "The possible misinterpretation of the SEM results arose because microanalysis in the SEM is not a surface-sensitive tool," says Kotula. "Because a spore body can be 1.5 to 2 microns wide by 1 micron long, a SEM cannot localize the elemental signal from whole spore bodies."
Using more sensitive transmission electron microscopy (TEM), Kotula and Michael's research indicated that the silica in the spore samples was not added artificially, but was incorporated as a natural part of the spore formation process. "The spores we examined," Kotula says, "lacked that fuzzy outer coating that would indicate that they'd been weaponized."
Sandia's work was the first to actually link the spore material in the New York Post, the Daschle and the Leahy letters. The elemental signatures and the locations of these signatures, while not indicating intentional weaponization, did show that the spores were indistinguishable and therefore likely came from the same source. That conclusion was corroborated a few years later by the DNA studies.
The materials characterization lab serves as a materials analysis resource for a diverse collection of projects. The lab plays an important role in stockpile surveillance, supporting Sandia's nuclear weapons mission.
Michael was recently released from his nondisclosure agreement and flown to Washington, D.C., to participate in press conferen
|Contact: Stephanie Holinka|
DOE/Sandia National Laboratories