Application of the immunofluorescent technique in testing the purity of Sendai virus.

Various attempts have been made in this laboratory to eliminate the host components surrounding Sendai virus particles. Procedures such as fluorocarbon treatment, sonication and methanol precipitation resulted in the loss of infectious titer of the test materials. However adsorption on and elution from chicken red cells or aluminum phosphate gel did not cause loss of infectious titer.1,2,3) Because of the hemolytic properties of Sendai virus when propagated in ovo, aluminum phosphate gel was chosen for purification purposes. Foundamental studies on this technique have been reported in the preceding paper .4) Highly purified preparations with regard to their hemagglutinin titers per mg nitrogen, showing a single component on ultracentrifugation, can be reproducibly obtained in this manner. The serological analysis of these preparations was then attempted. One of the serological procedures used for analysis of such preparations is the agar gel precipitin test, which has the advantage of differentiating various antigens.5,6,7) Another method is the immunofluorescent technique, which is a simple test of purity during purification. The present paper is chiefly concerned with the development of a immunofluorescent spot technique along the latter line using antibodies prepared against normal sedimentable materials.1