The pGEM®-3Zf(+) and pGEM®-3Zf(–) Vectors are derived from the pGEM®-3Z Vector and contain the origin of replication of the filamentous phage f1. These plasmids contain T7 and SP6 RNA polymerase promoters flanking a multiple cloning region within the α-peptide coding region of β-galactosidase. Insertional inactivation of the α-peptide allows recombinant clones to be identified directly by color screening on indicator plates when using appropriate E. coli strains (e.g., JM109). The multiple cloning region contains unique restriction sites for EcoRI, SacI, KpnI, AvaI, SmaI, BamHI, XbaI, SalI, AccI, HincII, PstI, SphI and HindIII. The pGEM®-3Zf(+) and -3Zf(–) Vectors are identical except for the orientation of the f1 origin and can be used as standard cloning vectors, as templates for in vitro transcription and for the production of circular ssDNA.
- Yanisch-Perron, C. et al. (1985) Gene 33, 103–19.