Comparative analysis of ELISA, nonradioactive molecular hybridization and PCR for the detection of prunus necrotic ringspot virus in herbaceous and Prunus hosts

Three methods were compared for the detection of prunus necrotic ringspot virus in herbaceous and woody plants: DAS-ELISA, nonisotopic dot-blot hybridization and reverse transcriptional polymerase chain reaction (RT-PCR). When purified virus preparations were used, the detection limit of the RT-PCR technique was 1·28 pg mL whereas nonisotopic molecular hybridization and DAS-ELISA allowed detection of 0·8 ng mL and 4 ng mL, respectively. Several sample processing procedures were evaluated for virus detection by the nonisotopic molecular hybridization technique. When a very short and simple sample processing method was used, the detection limit of the nonisotopic molecular hybridization technique was 25 times higher than that of DAS-ELISA and 625 times lower than that of RTPCR. A comparison of the level of virus accumulation in mature fruits and in leaf tissue showed that, on average, 125 times more virus was found in the fruits.