Low-cost paper can be used in tissue-blot immunoassay for detection of cereal and legume viruses

Abstract

In an effort to reduce the cost of virus assays, different types of regular paper were evaluated as possible replacements for the commonly used nitrocellulose membrane (NCM) as the solid phase in the tissue-blot immunoassay (TBIA) used to detect Alfalfa mosaic virus, Bean yellow mosaic virus and Broad bean stain virus (BBSV) in faba bean tissue, and Barley yellow striate mosaic virus in barley tissue. Among the many types of paper evaluated, Hewlett-Packard (HP) non-glossy plotter paper proved to be adequate for detection of all the above viruses. After printing (blotting) of the samples to be tested and blocking with either 2% gelatin (for one hour at 37oC) or using 0.1% Roche blocking reagent (for one hour at room temperature), satisfactory results were produced. This paper could also be used to detect BBSV in groups consisting of 15 young lentil seedlings. HP non-glossy plotter paper was not as effective when testing for phloem-limited legume viruses such as Bean leaf roll virus (BLRV), Faba bean necrotic yellows virus (FBNYV) and Barley yellow dwarf virus (BYDV). White paper (manufactured by Soporcel, Portugal) was slightly more sensitive when used for BLRV and FBNYV detection in faba bean tissues and for BYDV in barley tissues. Since NCM represents 40–50% of the cost of test reagents, using ordinary paper reduced costs considerably.