Detection and Enumeration of 42 NM Dane Particles by a Thin-Sectioning Procedure.

Abstract

Hepatitis B surface antigen (HBsAg) consists of three morphological forms identified by negative stain electron microscopy as spherical and rodshaped particles of approximately 22 nm diameter and double-shelled Dane particles of 42 nm diameter (Fig. 1). Dane particles contain DNA and are believed to represent the Hepatitis B virion while the smaller forms of HBsAg are thought to correspond to excess viral lipoprotein antigenically related to the surface of Dane particles. Electron microscopic studies of HBsAg in human blood plasma have always been carried out using negative staining techniques and Dane particles reportedly account for only a very small portion of HBsAg particles found in plasma. In the present study we demonstrate the usefullness of a previously devised thin-section virus particle counting technique (1) for detecting and enumerating Dane particles in either whole or partially purified blood plasma.