Measurement of antibodies to infectious avian encephalomyelitis virus by ELISA.
An enzyme-linked immunosorbent assay (ELISA) for the measurement of antibody to avian encephalomyelitis virus (AEV) is described. The wells of microtitre trays were coated with antibody to AEV, to which was bound a partially purified AEV preparation as an immunosorbent. The assay described is specific, in that antibody activity was not detectable in specific-pathogen-free (SPF) chickens except following inoculation with AEV. Inoculation of SPF chickens with a number of other viruses did not induce a detectable response. Furthermore, there was agreement between the ELISA and virus neutralisation test in terms of the rank order of a number of test sera and in the positive/ negative classification of sera. Both ELISA and virus neutralisation were capable of detecting an antibody response within 9 days of primary vaccination indicating that the ELISA was of comparable sensitivity to virus neutralisation. The amount of antibody in a sample was estimated relative to a reference serum preparation, and the results recorded as units of antibody activity. Using this method of data expression it has been possible to demonstrate that these assays are reproducible with little within-assay (co-efficient of variation = 5.6%) or between-assay (co-efficient of variation = 9.8%) variation for the mid-range sample.
Smart
I J
IJ
Department of Agriculture, Victoria Veterinary Research Institute, Parkville, Victoria, Australia.
Grix
D C
DC