Detection of Cymbidium mosaic potexvirus and odontoglossum ringspot tobamovirus using immuno-capillary zone electrophoresis

Immune-capillary zone electrophoresis (I-CZE) is a technique that combines the specificity afforded by serological assays with the sensitivity, rapidi ty, and automation in detection provided by capillary zone electrophoresis. Cymbidium mosaic potexvirus (CymMV) and odontoglossum ringspot tobamovirus (ORSV) were detected in their purified forms as well as in the crude saps of infected Nicotiana benthamiana leaves and Oncidium orchid flowers. The t wo orchid virus-antibody complexes were resolved via the combined actions o f electrophoretic migration and electro-osmotic flow along a buffer-filled, uncoated fused-silica capillary. The I-CZE fractions collected from both C ymMV- and ORSV-antibody complex peaks, as well as the RNA purified from the m, retained their infectivity upon inoculation onto Chenoponium quinoa. I-C ZE assays were able to detect as little as 10 fg each of both CymMV and ORS V in their purified forms as well as in the crude saps of infected N. benth amiana and Oncidium orchid. As multiple samples can be analyzed rapidly, I- CZE offers an ideal diagnostic technique for routine mass-indexing programs such as virus-free certification, breeding for virus-resistant cultivars, plant quarantine, and germ plasm screening. This is the first report of the application of I-CZE for the detection of plant viruses.