ELECTRON MICROSCOPIC OBSERVATIONS ON SH ANTIGEN USING POSITIVE STAINING

This chapter presents the electron microscopic observations on serum hepatitis (SH) antigen, which have been obtained using positive staining. SH antigen, which is identical with the Australia (Au) antigen, has been observed in the serum in acute and chronic liver diseases. Electron microscopy shows that this antigen is located on a 200 A spherical structure. The results of the experiments indicate that the outer membrane of the 430 A particles is similar to the membrane of the 200 A particles, in staining characteristics and morphology. Because only the central core of the large particle stains positively with uranyl acetate, only this form of SH containing particle can contain nucleic acid and possibly be a virus. The electron microscopic observations, based on differences in staining properties, indicate that only the larger of these particles might contain nucleic acid.