How to Prevent Adenovirus Aggregation

Adenovirus aggregation is a common issue during viral amplification, purification, concentration, and storage. Once adenoviral particles aggregate together, the virus may lose infectivity, produce lower functional titers, and show reduced consistency in downstream applications.

Several factors can contribute to adenovirus aggregation, including excessive viral concentration, harsh handling, repeated freeze–thaw cycles, improper buffer composition, and contamination with host-cell impurities.

Key strategies to minimize adenovirus aggregation:

• Avoid vortexing or harsh mixing of adenoviral preparations. Gentle inversion or slow pipetting is recommended.
• Minimize repeated freeze–thaw cycles by aliquoting virus stocks into single-use volumes.
• Store adenovirus at −80°C under appropriate formulation conditions.
• Use isotonic stabilization buffers containing salts and stabilizing agents rather than low-osmolarity buffers alone.
• Avoid over-concentrating adenoviral particles during ultracentrifugation or concentration steps.
• Resuspend viral pellets slowly and gently after centrifugation.
• Keep viral preparations cold during handling to maintain capsid stability.
• Properly remove host-cell debris, proteins, and residual DNA during purification, since impurities may promote particle aggregation.

Adenovirus is generally more stable in formulation buffers containing buffering salts, NaCl, MgCl₂, sucrose, glycerol, or surfactants than in simple low-osmolarity buffers such as 10 mM Tris alone.

Careful handling and optimized purification/storage conditions are critical for maintaining high infectivity and long-term stability of adenoviral vectors.