Freeze-drying is an effective method for preserving infectious type C retroviruses

Area of Science:

• Virology
• Biotechnology

Background:

• Retroviruses are RNA viruses that require specific storage conditions to maintain infectivity.
• Conventional storage methods often necessitate cold temperatures, increasing costs and logistical challenges.

Purpose of the Study:

• To evaluate the efficacy of freeze-drying (lyophilization) for preserving retroviral infectivity.
• To determine the long-term stability of lyophilized retroviruses at ambient temperatures.

Main Methods:

• Conventional freeze-drying techniques were employed.
• Sucrose stabilizer and gelatin were used as excipients.
• Infectivity titers of lyophilized retroviruses were assessed over time and storage conditions.

Main Results:

• Lyophilized retroviruses retained infectivity for over one year at room temperature.
• A 20-year-old sample of lyophilized Friend leukemia virus stored at 4°C showed high titers of infectious virus.
• The technique proved effective for preserving virus stability.

Conclusions:

• Freeze-drying is a viable and cost-effective method for preserving retroviral infectivity.
• Lyophilization eliminates the need for cold storage, facilitating easier shipping and long-term laboratory preservation.
• This technique is particularly beneficial for type C viruses.