Stabilization of erythrocytes by aldehydes and suitability of chicken IgY for the detection of potato virus X (PVX) in avidin-biotin enhanced reverse passive haemagglutination.

Methods are described for the detection of potato virus X (PVX) by reverse passive haemagglutination (RPH) by means of polyclonal antiviral antibodies coupled to sheep red blood cells (sRBC) and the chromic chloride method. The cells were stabilized with pyruvic aldehyde, thus providing a stock suspension for numerous coupling experiments lasting several months. Anti-PVX IgY, which is readily isolated in large amounts from the egg yolk of immunized chickens, was used in an avidin-biotin enhanced RPH assay with stabilized sRBC. With this method the PVX detection rate achieved was comparable to that of RPH assays using fresh non-fixed sRBC. In addition, avidin-coated sRBC could be stored for weeks at 4 degrees C and subsequently used for coupling with biotinylated IgY.