INOSINE 5'-TRIPHOSPHATE CAN DRAMATICALLY INCREASE THE YIELD OF NASBA PRODUCTS TARGETING GC-RICH AND INTRAMOLECULAR BASE-PAIRED VIROID RNA

Nucleic acid sequence-based amplification (NASBA) according to the sta ndard protocol failed to amplify cRNA of viroids, probably because of their CC-rich and intramolecular base-paired structure. However, NASBA in the presence of inosine 5'-triphosphate successfully amplified the cRNAs to viroids in total nucleic acid extracts from citrus plants. A s sequence specificity of the cRNA to viroids was confirmed by norther n analysis, the amplification and fidelity of cRNAs are sufficient for the sensitive and specific detection of viroids.