[Determination of an ELISA test on tissues of grapevine affected by yellow disease]

We report here results concerning the best part of the grapevine to section, the best sampling period and an important adaptation of the extraction media for the diagnosis of a grapevine yellow disease by ELISA. The addition of Triton-X100, or better of Chaps enabled us to get clear results for the sensitive Vitis vinifera scion varieties. Until now, results have not been obtained for the symptomless root stock varieties. However, antigen concentration by molecular filtration may be a way to solve the problem of assaying root stocks.