Q: Can you please help me understand the safety risk of a pseudo-virus and how it might compare to the safety level of a non-replicative lentivirus or retrovirus?
A: Because PsV are capable of transferring foreign DNA, they should be handled using full biosafety level 2 precautions. It is important to note that the promiscuity of packaging by L1 and L2 can lead to generation of PsV with encapsidated fragments of cellular DNA, possibly including SV40 large tumor antigen, adenovirus oncogenes, or unknown oncogenes present in 293TT cells. Mature PsV can be inactivated by 70% ethanol, but, like many other types of non-enveloped virus particles, they are resistant to a wide spectrum of physical insults, including various detergents and proteases, prolonged heating at 56°C, 50 mM EDTA, and sodium chloride up to at least 1.5 M (unpublished results). PsV are probably also resistant to dessication. High-titer PsV should never be harvested using tip sonication, which can create potentially dangerous aerosols.