Summary of in-process characterizations of EV71 vaccine bulk produced from serum-free medium.

ND: not determined. aTCID50 is the median tissue culture infective dose of EV71 that produces pathological cytopathic effects (CPE) in 50% of inoculated cell cultures. bTotal protein concentration was determined by the BCA protein assay. cVP2-specific epitope content was determined by Q-ELISA [19]. dRecovery was calculated using the total VP2 epitope content at each step divided by the total VP2 epitope at the harvest stage. ediafiltration/concentration step. fgel-filtration chromatography purification.