Abstract
Preparations of poliovirus I and echovirus 7, purified by density gradient centrifugation, liquid-phase partition, and anion exchange (diethylaminoethyl) chromatography, have been shown to evoke high antibody levels of substantial specificity in the complement-fixation assay. Certain practical aspects of the three purification methods are discussed. These results argue for the use of purified viral antigens, particularly in view of the simplicity of the purification methods now available.