Labeling Techniques in the Diagnosis of Viral Diseases.

The principle underlying the use of labeled antibody in the study of cellular antigens, both natural and foreign, is well understood. Recent reviews have been published by Liu (9), Poetschke (14), Hers (7), and Mims (13). Moreover, a review of the whole field of the use and abuse of fluorescent antibody was published by Beutner in 1961 (1). It is the purpose of this presentation to call attention to some of the uses of immunofluorescence by virologists in recent years, and to single out certain aspects which seem of interest. Although a cell infected with a virus was first specifically stained with antiviral antibody in 1948 (3), fluorescent antibodies have scarcely been employed in the rapid diagnosis of virus infections. The reason for this, I suppose, is because such information is ordinarily not necessary since no treatment is available. Perhaps for the time being the specific diagnosis is of immediate concern only for rabies and smallpox. In the case of rabies, where the diagnosis is important because it affects that vigor of the treatment, Goldwasser and Kissling (6) made an important step by showing that rabies virus could be positively identified in brain tissue and salivary tissue and salivary glands by the use of immunofluorescence. As specific antisera, they used sera from human beings who had been immunized with rabies vaccine derived from duck embryos. They stated that they could identify rabies virus with such specific antiserum, either by the direct method or by the use of antiglobulin or anticomplement fluorescein-labeled antibodies. Incidentally, they found that Negri bodies contained high concentrations of viral antigens throughout their substance. They also demonstrated that small eosinophilic inclusions which could not be considered specific by standard histological methods in fact contained rabies antigen. They found rabies virus in the salivary