A Novel Image Analyzer of SRID Assay for the Quantification of Hemagglutinin in Influenza Vaccine

The single radial immunodiffusion (SIRD) assay has been adopted internationally for the assay of influenza vaccines to estimate their HA antigen content. To measure SRID reaction zones, the virology department of company currently uses a sliding caliper viewer to manually calculate the size of SRID reaction zones, which is a time-consuming, labor-intensive and error-prone task, so the manually method is not suitable for GMP quality control standards. In this article, we describe the development of a novel method for automatically quantifying hemagglutinin assessed by SRID. The antigen or antibody content is calculated through serial steps including reaction zones image input, data collection, data analysis, error analysis, data storage and output. The image analyzer is authenticated in the aspects of linearity, reproducibility and recovery rate. The result of linearity assay shows that the correlation coefficients of the standard curves generated all exceed 0.99 and the average relative deviation is 1.14%. The result of reproducibility assay shows that the image analyzer has better reproducibility. The recovery rate calculated by the image analyzer is equal to the actual and the average relative deviation is less than 1%.