 This EID50 assay is used to quantify titer for many viruses that can be grown in eggs.A simple method of estimating fifty percent endpoints.The measurement of virus titer obtained from this assay is expressed as an embryonic infectious dose 50% (EID50).The SeV titer can also be assessed by using plaque assay in LLC-MK2 cells and by serial end point 2x dilution hemagglutination assay (HA).