Electron Microscopy of Poliovirus Antigen Antibody Precipitates Extracted from Gel Diffusion Plates

Two antigens detected in poliovirus preparations are called either N (native) or H (heated) or D and C from their position in a density gradient. Most of the infectivity and RNA of poliovirus preparations is in the D zone on gradient centrifugation and virus inactivation by heat or mercuric ions changes the antigenic reactivity from N or D to H or C with release of viral RNA (Le Bouvier, 1959; Dimmock, 1967). Hummeler, Anderson & Brown (1962) showed by electron microscopy that empty virus particles (penetrated by phosphotungstate) were aggregated by antiserum to heated virus and full virus particles (not penetrated by phosphotungstate) by antiserum to native virus. Watson et al. (1966) described a method of examining virus precipitin lines under the electron microscope, and we have examined the D and C antigen precipitates of type 1 poliovirus by this technique.

Plate 1 shows a gel diffusion test prepared as described by Beale & Mason (1962).