Titration of Newcastle disease virus and its neutralizing antibodies in microplates by a modified hemadsorption and hemadsorption inhibition method.

Assay of human interferon in Vero cells by several methods.

Four methods for the assay of human interferon in Vero cells were compared based on the inhibition of viral cytopathic effect (CPE) in tubes, the inhibition of CPE in microplates, the reduction of plaques, and the inhibition of quantitative hemadsorption. For inhibition of CPE, Sindbis virus, vesicular stomatitis virus, poliovirus type 2, and vaccinia virus were used for challenge. In the plaqu...

Comparison of Micro Neutralization Test with Hemadsorption-Inhibition Test, and Immunoflrorescence Technique for Detecting Mumps Antibodies

Hemadsorption-negative plaque test: new assay for rubella virus revealing a unique interference.

A simple and rapid plaque procedure has been developed for detecting and accurately assaying rubella virus in a noncytopathic virus-cell relationship. Plaque-formation is based on the development, in individual cells infected with rubella virus, of a unique type of intrinsic interference to infection with Newcastle disease virus. Rubella virus-infected cells challenged with Newcastle disease vi...

Primaquine diphosphate: inhibition of Newcastle disease virus replication.

The response of Newcastle disease virus replication to primaquine, an antimalarial drug, was examined in chicken embryo cells (CEC). Virus-induced hemadsorption was completely inhibited by 250 mug of primaquine per ml. At lower concentrations, hemadsorption inhibition was dose dependent. Primaquine retarded virus-induced redistribution of receptor sites on the host cell plasma membrane as shown...

Generation and Biological Characterization of a Neutralization-Resistant Mutant of Newcastle Disease Virus

A neutralization-resistant mutant of Newcastle disease virus (NDV) Kr005 strain belonging to class II genotype VII was generated using a neutralizing monoclonal antibody and its biological effects were assessed. The mutant showed single amino acid substitution (E to K) at position 347 of the hemagglutinin-neuraminidase (HN) protein (E347K mutant). The E347K mutant exhibited marked rounding of t...