Quantitative detection of Potato viruses X and Y (PVX, PVY) with antibodies raised in chicken egg yolk (IgY) by ELISA variants

The suitability of purified antibodies raised in chicken egg yolk (IgY) for the detection of PVX and PVY was compared with poly- and monoclonal antibo dies from mammalians in two ELISA variants as coating- or 2(nd) antibody. A lso IgY were rendered virus-monospecific (IgY(msp)) by cross adsorption wit h virus by a batch method and thus ELISA sensitivity was doubled. The compa rison was made on the basis of the detection limit of CsCl-gradient-purifie d viruses first in a model system (virus in buffer) with all ELISA paramete rs quantified. The lowest virus quantity eliciting A(405nm) 0.1 was defined as detection limit of the assay. Virus was then detected in sap of infecte d plants with IgY and IgY(msp) and the virus concentration/g leaf tissue de termined. When extensively compared with IgG from mammalians, the IgY were equally suited for virus detection. Moreover, IgY can be raised and purifie d Less laboriously and in about 40-fold larger quantity than IgG from rabbi t serum.