ADENOVIRUS AGGREGATION AND PRESERVATION IN EXTRACELLULAR ENVIRONMENT

The conditions of adenovirus aggregations are analyzed. Adenovirus type 2 was propagated on Hep2 cells; virion aggregation analysis was performed by sedimentation velocity on sucrose gradients. The results show that aggregation depends on: 1) Ionic strength: aggregate formation was verified between 0.005 M and 0.05 M NaCl; 2) pH: at pH 7.1 virus particles are dispersed, 90 per cent of particles are aggregated at pH 4-5; at pH lower than 4 aggregation is not reversible; 3) Particle concentration: the dilution of a stock containing 5×1011 particles/ml decrease rate of aggregate formation until all aggregation is inhibited; 4) Temperature: the degree of aggregation in the 25 to 37°C range is constant but decreases when the temperature falls below 20°, at +4°C there is no aggregation. The aggregation reaction presents a positive ΔH of 17.9 Kcal/mol and a ΔG of -1.32 Kcal/mol. © 1979 Springer-Verlag.