pCMV Plasmids

pCMV plasmids are widely used vectors in molecular biology for gene expression studies and transient transfection applications. The key feature of these plasmids is the presence of the CMV (Cytomegalovirus) promoter, which drives high-level expression of inserted genes in a broad range of mammalian cells.

Key Features

• CMV Promoter: The CMV promoter is a strong, constitutive promoter derived from the cytomegalovirus. It drives high levels of gene expression in a wide variety of mammalian cell types, including both dividing and non-dividing cells. This makes pCMV plasmids ideal for transient transfection experiments where high expression levels are desired.
• Expression Cassette: The plasmid includes an expression cassette, which comprises:
  • CMV Promoter: Drives transcription of the gene of interest.
  • Gene of Interest: The insert, which could be any gene or coding sequence intended for expression studies.
  • Polyadenylation Signal: Typically derived from the SV40 or other sources, this sequence ensures proper termination and polyadenylation of the mRNA, increasing stability and expression.
• Selectable Markers: To facilitate the selection of transfected cells, pCMV plasmids may contain selectable markers such as:
  • Antibiotic Resistance Genes: Commonly used markers include genes for resistance to neomycin (G418), hygromycin, or puromycin.
• Multiple Cloning Site (MCS): Located downstream of the CMV promoter, the MCS contains multiple unique restriction sites allowing for the insertion of various DNA fragments or genes.
• Origin of Replication: pCMV plasmids generally include a replication origin that allows them to replicate within bacterial cells, such as the pUC origin or similar, ensuring high plasmid yield during bacterial propagation.

Content

• Backbone: Includes CMV promoter, MCS, selectable marker, and polyadenylation signal.
• Promoter: CMV promoter for driving gene expression.
• Gene of Interest: The insert you wish to express.
• Selectable Marker: Antibiotic resistance gene to select for successfully transfected cells.

Applications

• Transient Transfection: Ideal for experiments where high-level expression of a gene is needed for a short period. Useful in assays, protein production, and functional studies.
• Protein Production: Suitable for producing recombinant proteins in mammalian cells.
• Gene Function Studies: Allows for the investigation of gene function, signaling pathways, and protein interactions.
• Reporter Assays: Can be used with reporter genes (e.g., luciferase, GFP) to study promoter activity, gene regulation, and cellular processes.