Lentivirus and AAV should be stored immediately at -80°C. For long-term storage, store the virus in the back of the freezer where it is less likely to be influenced by temperature changes associated with opening the freezer door.
Addgene does not recommend subjecting your viral preparation to multiple freeze-thaw cycles as this can reduce the titer. However, if you plan to use the virus for multiple experiments, thaw the viral preparation, aliquot the desired volume, and snap-freeze in liquid nitrogen or a dry ice/ethanol bath before storing at -80°C.
Virus stability at -80°C varies depending on the media composition and the virus identity. Once you receive your virus, Addgene recommends using the viral preparation within one year.
For more information on how to use your virus and other useful links, visit our Recipient Instructions page.