DETECTION OF HEPATITIS-A VIRUS BY A DIGOX IGENIN-LABELED RIBOPROBE AND COMPARISON WITH OTHERS VIROLOGICAL METHODS

A riboprobe (RNA probe), corresponding to the 5' end of the HM175 hepa titis A virus (HAV) genome, was synthetized in vitro and was digoxigen in-labeled. Then the riboprobe was used to detect the CF53 HAV strain. Conditions of virus denaturation (with or without SDS and proteinase K, timing of assay) to release viral RNA were tested by dot-blot hybri dization on a ten fold dilution of HAV suspension. Densitometric measu res of dot-blot spots allowed to appreciate optimization of the method . Sensitivity of hybridization was compared with sensitivity of radioi mmunoassay (RIA) and cell culture methods. Hybridization signals and s cale of HAV suspension were consistent when 0.05% SDS, 0.17 mug/ml Pro teinase K, 37-degrees-C, 30 mn or 3 hours are used. 8.10(2) TCID50 HAV was detected by hybridization with digoxigenin-labeled RNA probes. De tection threshold was the same as radioimmunoassay and lower comparati vely to cell culture.