Product Name: pSF-CMV-BetaGal-RSV-Puro
Product Code: OG594
Size (bp): 8580 bp
Bacterial Antibiotic Selection: AmpR
Origin and Compatibility: pUC high copy derived from pBR322
Bacterial Copy Number: 500-700 per cell
Promoter: Cytomegalovirus (CMV) immediate early promoter / Rous Sarcoma Virus LTR Promoter
In this plasmid the beta galactosidase reporter gene is under transcriptiona l control of the strong mammalian CMV promoter and puromycin resistance is expressed from a separate expression cassette under control of the strong mammalian RSV promoter.Promoter Expression Level:
This plasmid contains the mammalian CMV promoter to drive gene expression. We have tested all of our mammalian promoters in a range of cell types and CMV is consistently the strongest in those we have studied. However there are many reports of the CMV promoter demonstrating silencing by methylation in long-term culture. For this reason we stock a range of other promoters that are compatible with this plasmid and are available on request. The RSV promoter driving reporter gene expression is one of the weakest mammalian promoters that we provide for many cell types but expression can vary significantly between cell types from different species. For example we have found that the RSV promoter shows significantly lower expression levels in human 293 cells when compared to hamster CHO cells.
This plasmid contains three alternative transcription terminators for mammalian bacterial and bacteriophage (T7) expression. This means that only the promoter needs to be changed to alter the expression system you are using. We sell multiple promoters that can be used in each of these systems. The presence of each terminator does not reduce expression in the alternative systems.
This plasmid contains a gene within the main multiple cloning site (NotI-ClaI). Any plasmid that we sell where the gene is this configuration will be located in the exact same position in relation to the start and stop codon of the gene. The only exceptions to this rule are fusions proteins where the fusion gene may be positioned at the front or end of the MCS to allow gene fusion.
By positioning all of our genes in the same location it allows them to be transferred between plasmids using the same cloning method and restriction sites regardless of the plasmid being used from our product range. Inserting a new gene into this plasmid should be easily possible using a range of standard restriction enzyme sites that flank the gene currently in the vector.Multiple cloning site notes:
In the multiple cloning site there are two important restriction sites called BsgI and BseRI sites. These sites both cut the DNA at the same position and cleave the stop codon of the gene in the multiple cloning site in this plasmid thereby producing a TA overhang. This overhang is compatible with any of our peptide or reporter fusion tag plasmids also cut with either of these enzymes. This allows seamless C-terminal fusions to be made with the gene in this multiple cloning site using a single cloning step from our C-terminal peptide and reporter tag product range. Normally the easiest method is to clone the C-terminal tag from our other plasmid products into this plasmid using BsgI or BseRI and the downstream ClaI restriction site.
BseRI and BsgI sites are non-palindromic and cleave a defined number of bases away from their binding sites. This allows them to cut the upstream stop codon in the gene in this plasmid regardless of the gene sequence.