Complement-Fixation Test for Detection of Viral Antibodies in Chicken Serum. I. Standardization of the Test for Detection of Antibodies to Newcastle Disease Virus and Polyoma Virus

Abstract

A modified direct complement-fixation (CF) test is described for the detection of serum CF antibodies to Newcastle disease virus (NDV) and polyoma virus in chickens made hyperimmune to these viruses. Fixation of the guinea pig complement (gpc') by the virus antigen-chicken antibody required the addition of an optimal dilution of unheated normal chicken serum (NCS) to the gpc' at the time of its addition to the test. Partially purified antigens were required for the test and the technique for their preparation is described. The NCS could be stored at -70 C for 12 months without any detectable decrease in activity but at 4 C had a partial loss of its titer-enhancing ability within 24 hours but no further loss in the next 48 hours.