Measurement of surface antigen by specific bacterial adherence and scanning electron microscopy (SABA/SEM) in cells...

Temperature-sensitive (ts) mutants of the rhabdoviruses vesicular stomatitis virus and Chandipura virus have been used to measure the appearance of virus antigen on the surface of infected cells by the technique of surface analysis by bacterial adherence and scanning electron microscopy (SABA/SEM). The number of staphylococci specifically adhering to antiserum-treated infected PTK-2 or BSC-1 cells at permissive (31 degrees C) and restrictive (39 degrees C) temperatures was followed in time-course experiments and a close correspondence was observed between the proportion of staphylococci bound at 39 degrees C and the known phenotypic properties of the ts mutants. Virus surface antigen was undetected in cells infected by transcription- and replication-defective ts mutants with thermolabile L proteins under restrictive conditions up to an input multiplicity of infection of 50, and in cells infected by a replication-defective NS protein mutant. Some surface antigen was detected late in infection in PTK-2 cells infected by a replication-defective N protein mutant. Surface antigen accumulated normally in maturation-defective mutants with lesions in envelope proteins. These results establish the suitability of the SABA/SEM technique for quantitative estimation of virus antigen on the surface of infected cells.