Dense Granule in the Elementary Body of Molluscum Contagiosum

Samples of tissue from molluscum contagiosum lesions were fixed in 1 per cent buffered osmium tetroxide (1) for 3 hours, then washed in veronalacetate at pH 7.3 for 21/~ hours, dehydrated in graded alcohols, and embedded in methacrylate. Thin sections of this material were taken for study in the electron microscope. A small dense granule was found within the elementary bodies contained in these lesions. Elliptical, round, or lancet-shaped, the granule ranges in size from ,-'8 to 11 m# in width and ~11 to 20 m# in length, but is usually about 8.5 x 11 mlz (Figs. 1 and 2). The granule is often situated eccentrically in a less dense area of variable, but small size which, in section, may be round, oval, slit-like, straight, or crescentic. The granule is most commonly associated with the thicker portions of one of the side walls of the elementary body and is often situated within the wall in the condensed mature elementary body. It may also be seen, however, on the inner membrane, or even within the less dense central area. In the swollen form of the virus (Fig. 3), the granule may be present within the enlargements of the wall or, somewhat less frequently, within the clear central area of these large forms. The granule is occasionally present in the dense, spherical forms of the developing elementary bodies that