Research Note: A Rapid Macroscopic Plate Agglutination Test for Newcastle Disease. A Preliminary Report

Abstract

RAPID and simple macroscopic test to detect antibodies against animal viruses would be of value in human and veterinary medicine. This paper (1) describes a plate agglutination test to detect antibodies for Newcastle disease (ND). The antigen was prepared from centrifuged chorioallantoic fluid of embryonating chicken eggs infected with the GB (Texas) strain1 of ND virus. Eighty 9-day-old embryonating eggs were inoculated via the chorio-allantoic route with one million ELD50 of the GB (Texas) strain of ND virus. The chorio-allantoic fluid (360 ml), harvested at death of the embryos 18 hours or more after inoculation, was differentially centrifuged. Extreme care was taken in harvesting asceptically only the chorio-allantoic fluid. If yolk material was aspirated by accident, the syringe was discarded. Another clean, sterile syringe and needle were used to continue the harvest. This was pooled into a 500 ml. sterile Erlenmayer flask, partially immersed in ice water. The temperature of the cubicle during harvesting was approximately 28 C. One cardboard flat of eggs (30 eggs) was harvested at a time. The remaining dead eggs were kept at 2 C until harvested. A suitable sample of the pooled chorio-allantoic fluid had an ELD,, of 10-9-0. Shortly after harvesting, the 360 ml of