Photometric Methods for the Measurement of Hemagglutinating Viruses and Antibody

Abstract

Summary: A photometric method for titration of virus using equipment available in this country has been described. The standard deviation of mean titer values found in a series of replicate titrations carried out in one laboratory was 3.5%. The average difference in titer values found in three different laboratories using several strains of virus was 7.87%. Such reproducibility has not previously been achieved and the use of the method may permit development of an international standard for measurement of hemagglutinin.