Application of nucleic acid aptamers for detection of Apple stem pitting virus isolates

DNA aptamers (PSA-H and MT32) were applied for the detection of Apple stem pitting virus (ASPV) isolates using an Enzyme-Linked Oligonucleotide Assay (ELONA) and Western blot analysis. The specificity and effectiveness of aptamers were verified in comparison to a conventional Enzyme Linked Immunosorbent Assay (ELISA). A genetically diverse group of ASPV isolates was tested. The results showed that aptamer MT32 detected a wider range of ASPV isolates than an aptamer PSA-H and proved to be superior to commercially available monoclonal antibodies. Aptamer MT32 produced higher signal intensity in ELONA with a virus-infected plant extracts than antibodies in ELISA. Moreover, the ELISA method failed to detect ASPV in six samples. The results presented in this study indicated that aptamer MT32 can be used as a receptor molecule of various immunoassay protocols for ASPV detection.