THE EFFECT OF CHANGING SINGLE RADIAL HEMOLYSIS ASSAY-METHOD WHEN QUANTIFYING INFLUENZA-A ANTIBODIES IN SERUM

Single radial hemolysis (SRH) is a simple method for measuring concent rations of antibody specific for influenza A viruses, There are many d ifferences in reported assay methods and these changes may significant ly affect results, This study evaluated the effect of changing erythro cyte concentrations, influenza virus concentrations used to sensitize erythrocytes, incubation times, and incubation temperatures, These fac tors were shown to significantly affect results of the SRH assay. A me thod for standardizing the assay and expressing results as relative an tibody concentrations is described. Standardized relative antibody con centrations show significantly less variability than do hemolysis zone measurements when the SRH assay method is changed. This paper demonst rates that use of this method would allow for more consistent results to be obtained within laboratories. Use of this method with quantified , internationally standardized sera would allow results of the single radial hemolysis assay to be directly compared between laboratories.