... change, the supernatant containing the viral particles is removed and stored or centrifuged to concentrate...types and enhances the stability of the viral particles. However, VSV-G is toxic under long-term, constitutive...Gamma-retroviral vectors have been shown to be safe delivery vehicles and provide stable integration of the intended...cell genome but cannot produce functional viral particles without the genes encoded in the envelope and ...that resulting construct is packaged into a viral particle, it is not possible for viral vectors to replicate...Precursor structural protein of the retroviral particle containing matrix, capsid, and nucleocapsid components...