Antibody in SSPE serum and brain igG against measles virus smooth nucleocapsids detected by immunoelectron microscopy

SSPE patients characteristically have high complement-fixing (CF) and neutralizing (N) antibody titers against measles virus in their sera, CSF, and brain. However, using SSPE patients' sera, the immunoperoxidase (IP) labeling of smooth nucleocapsids in SSPE or measles virus infected Vero cells or measles virions has not been achieved using conventional EM fixatives. Using the periodate-lysine-paraformaldehyde (PLP) fixative developed by McLean and Nakane (1974), and the indirect IP technique, antibodies against smooth nucleocapsids in SSPE and measles virus infected Vero cell cultures have been detected in serum from SSPE patients and normal individuals with high measles antibody titers.