A simple kit for rapid field diagnosis of potato virus Y by latex serological test

A simple kit for rapid detection of potato virus Y by latex serological test was developed. The test is carried out on a white cardboard sheet and the results can be read by naked eye in two minutes. A test card of 10 x 6 cm holds latex sensitized antibodies, buffers and other necessary ingredients as dry blue colored formulate on the ringed areas of the card. A test card includes space for six tests and positive and negative controls. The kit also includes disposable plastic sticks for mixing the samples with test reagents and a hand press with disposable plastic tips. For testing, dried reagents are dissolved in drops of sample and mixed. After gentle rotation, samples containing virus appear clearly granulated while samples from healthy plants remain unagglutinated. The testing of undiluted extracts of evenly developed tuber sprouts resulted in over 91 % identity with the results obtained with ELISA that was used as a control method. Testing of diluted leaf extracts reached the same reliability but undiluted leaf extracts from glasshouse grown potatoes were not well suitable as test samples because of their dark green color. No such problems occurred with field grown material and a complete identity with the ELISA readings was true when the samples included secondarily infected potato plants. No reaction to other potato viruses than PVY was obtained by the test kit.