The Lentivirus that we use is derived from the Human Immunodeficiency Virus (HIV), but has been stripped of its virulence genes, eliminating pathogenicity while still having the capacity to infect cells. Furthermore the virus genome has been split into several vectors allowing a safer method of transfection.

Lentivirus is considered one of the best methods to expressing trans-genes, this includes expression of open reading frames (ORFs), small hairpin RNAs (shRNAs) and guide RNAs (sgRNAs). Lentivirus can infect both dividing and non-dividing cells allowing integration of their genetic cargo directly into the chromosome of the target cell. Once integrated, trans-gene can be expressed, but no new virus can be made.