title: Detection of helper virus in retrovirus stocks.
abstract: Helper virus is a replication-competent virus that is sometimes present in stocks of replication-incompetent virus. There are several types of applications in which the presence of helper virus can be problematic. If animal infections are being done, helper virus can lead to leukemia, particularly if the infection is carried out pre- or neonatally. If retroviruses are being used for lineage analysis, helper virus may cause horizontal spread of the marker virus, creating false lineage relationships. This unit describes protocols for the detection of helper virus by a selectable marker assay, by rescue of an integrated provirus, or by measuring reverse transcriptase activity.
authors.affiliation: Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: C
authors.initials: C
authors.lastname: Cepko
authors.forename: W
authors.initials: W
authors.lastname: Pear
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002642:Chick Embryo; D024882:Drug Resistance, Viral; D005347:Fibroblasts; D006378:Helper Viruses / Q000302:isolation & purification*; D007202:Indicators and Reagents; D051379:Mice; D011533:Proviruses / Q000254:growth & development / Q000502:physiology; D012194:RNA-Directed DNA Polymerase; D012190:Retroviridae / Q000254:growth & development*; D014779:Virus Replication
chemical_list: D007202:Indicators and Reagents; D012194:RNA-Directed DNA Polymerase