Studies of rotavirus particles in humans, monkeys and various
non-primates with acute gastroenteritis have involved detection of virus in
fecal material by electron microscopy. The EM techniques most commonly
employed have been the conventional negative staining (Fig. 1) and immune
aggregation (Fig. 2) procedures. Both methods are somewhat insensitive and
can most reliably be applied to samples containing large quantities of virus
either naturaLly or as a result of concentration by ultracentrifugation. The
formation of immune complexes by specific antibody in the immune aggregation
procedures confirms the rotavirus diagnosis, but the number of particles per
given microscope field is effectively reduced by the aggregation process. In
the present communication, we describe use of an on-grid immunoelectron
microscopic technique in which rotavirus particles are mounted onto
microscope grids that were pre-coated with specific antibody. The technique
is a modification of a method originalLy introduced by Derrick (1) for
studies of plant viruses.