Studies on the physical, chemical & diological properties of viral haemolysin & haemagglutinin of some members of paramyxo virus group

This work was an nttempt for a comperat1ve study between haemolysis and haemagglutinationof some membersof paramyxevirua group. The work included a study about the development of haemolysin and haemogglutin in emb-ryonated chicken eggs for Newcastle disease virus (three strains of different pathogenicity). Clrainfluenza I (Sendai\strain),and mumps viruses.Results of this experiment showed that the allanteic fluid is the part in which the virus shown maximum and earfor presence of the virus while 24 hours are needed for the lentogenio strain.It could be resulted from this experiment that haemolysis test can be more sensitive than haemoagglutinationtest. The ~aemolysis test can be possitive even if the amount of virus present is less than r06 virion which is the leastamount of virus showing itself in the haemagglutination testas I H A unit.This result is also clear in the test of the minimum haemolytic dose. Haemolytic idex (HL:H.A ratio) may give idea about the pathogenicity of the strain tested,it was found to be around” 5 for the velegenic strain of Newcastle disease virus.