title: Aggregation of enterovirus small plaque variants and polioviruses under low ionic strength conditions.
abstract: Virion aggregation in low ionic conditions was observed with small plaque variants of Coxsackievirus type B3 and Echovirus types 4 and 11 by sedimentation and filtration methods. Inclusion of salts or DEAE-dextran into the media prevented or reversed virion aggregation. The effect of pH on aggregate formation in low ionic strength solutions was also investigated with various strains of poliovirus. Type I Sabin strain formed aggregates even at high pH, while Mahoney strains did so only below pH 6.5. Type 2 virus, Sabin and MEF1 strains, and type 3 virus, Sabin, Saukett and Suwa strains, showed an intermediate behaviour between the two type 1 strains, except MEF1-LB strain, a clone obtained from MEF1 strain under acidic overlay, which showed little tendency to aggregate. These results were compared with the degree of the d character of the strains. Besides the effect of inhibiting virion aggregation, the inclusion of DEAE-dextran into a sucrose gradient slowed the sedimentation of some of the viruses in low ionic strength solutions.
mesh_terms: D002460:Cell Line; D002499:Centrifugation, Density Gradient; D003637:DEAE-Dextran; D004770:Enterovirus / Q000254:growth & development / Q000302:isolation & purification*; D029822:Enterovirus B, Human / Q000254:growth & development / Q000302:isolation & purification*; D014644:Genetic Variation; D008851:Micropore Filters; D009994:Osmolar Concentration; D017955:Poliovirus / Q000254:growth & development / Q000302:isolation & purification*
chemical_list: D003637:DEAE-Dextran