A Small Hemagglutinating Component in Preparations of Newcastle Disease Virus.

Abstract

Disproportionate sedimentation in the high speed centrifuge of hemagglutinins and infective principle of Newcastle disease virus in suspensions of infected allantoic membranes was reported. This suggests the presence in such prepns. of 2 hemag-glutinating particles of different sizes; one appears to be identical with the infectious principle, the other, smaller one according to all indications is non-infectious. The specificity of this smaller hemagglutinin has been established by hemagglutination-inhibition tests. The medium in which the virus is suspended apparently does not affect the sedimentation of hemagglutinating capacity. Expts. employing Seitz filtration were unrevealing.