[Accelerated method of detecting antibodies to tick-borne encephalitis and Isfahan viruses on fixed smears of antigen-containing cells].

A modification is suggested of the indirect method of fluorescent antibodies (IMFA) for rapid diagnosis of the TBE and Isfagan viruses in fixed smears of antigen-containing cells. Preparation of such smears with equal numbers of antigen-containing cells in a monolayer covering the whole area of the depression inoculated with the infected cellular suspension ensures standard conditions for the test and comparable results. The titer of the sera in the smears determined with the IMFA is higher or similar to that obtained in the infected monolayer cultures grown on slides. One preparation can be used not only for the serum antibody identification but also for its titration. It takes no more than 4-5 hours to analyse the test sera. The fixed preparation with the antigen-containing cells can be stored during 6 months at -20 degrees C with no specificity lost. Availability of such preparations in stock will permit the IMFA to be applied in rapid diagnosis.