Under a low magnification of 37x, this 2007 scanning electron micrograph (SEM) depicted the fibrous configuration of a dry macrofoam sponge swabs. This swab, as well as three other materials, including polyester (see PHIL 9735), rayon (see PHIL 9734) and cotton (see PHIL 9732, and 9733), were scanned for a CDC study involving their efficiency in recovery of Bacillus anthracis bacterial spores from steel coupons that had been inoculated with a spore suspension of known concentration. See PHIL 9736, 9737, 9738, 9750, 9751, an 9752, for other views of this material. The article discussing the description of this swab material analysis, and the analytical results was published in Emerging Infectious Diseases, Vol. 10, No. 6, June, 2004, and was entitled, Swab Materials and Bacillus anthracis Spore Recovery from Nonporous Surfaces. A link to this article is found below.