Anthrax Under The Microscope
 
 

Tuesday, November 5, 2002; Page A24

The Oct. 28 front-page article "FBI's Theory on Anthrax Is Doubted" reported that silica enabled anthrax spores sent through the mail last fall to become airborne. The article quoted unnamed sources as saying that the spores had been formulated with a product called fumed silica, which, under an electron microscope, "would look like cotton balls strung together into strands that branch out in every direction."

Both of us have examined electron micrographs of the material in the anthrax letter sent to Sen. Tom Daschle, but we saw no evidence of such balls or strands. In July 1980, the Journal of Bacteriology reported an "unexpectedly high concentration of silicon" to be naturally present in the outer spore coat of bacillus cereus, a close relative of bacillus anthracis. Is it possible that the unnamed sources misinterpreted silicon naturally concentrated in spore coats as something that was artificially added?

Until knowledgeable government investigators announce their results, statements attributed to anonymous sources or from persons who have not examined the actual evidence should be greeted with caution.

MATTHEW MESELSON

Department of Molecular and Cellular Biology

Harvard University

Cambridge, Mass.

KEN ALIBEK

Center for Biodefense

George Mason University

Manassas