Production of a rabbit anti-cockatiel immunoglobulin G and characterization of its cross-reactivities with immunoglobulin G of other psittacine species.

The purpose of this work was to produce rabbit anti-cockatiel immunoglobulin G (IgG) and compare its cross-reactivity with sera from eight other psittacine birds: Quaker parakeet, budgerigar, green-wing macaw, blue-fronted Amazon parrot, eclectus parrot, African grey parrot, Patagonian conure, Moluccan cockatoo. Cockatiel IgG did not bind to protein A or G; therefore, these proteins could not be used in column chromatography to isolate the IgG. A combination of serum IgG precipitation by ammonium sulfate and yolk IgG extraction from egg was loaded in sodium dodecyl sulfate-polyacrylamide gel upon which the IgG was resolved by electrophoresis. The resolved IgG in sodium dodecyl sulfate-polyacrylamide gel was stained with Coomassie blue, cut, crushed in phosphate-buffered saline, and injected into rabbits. The rabbit anti-cockatiel IgG produced in this way reacted with a single protein in gel immunodiffusion assay with all nine psittacine bird sera but not with those of chicken and ostrich. Immunoelectrophoresis confirmed the cross-reactivity of different psittacine sera with the anti-cockatiel IgG serum but not with ostrich and chicken sera. This antiserum detected antibody responses in sera from cockatiels vaccinated against chlamydial major outer membrane protein in an immunoblot assay.