pSF-Tac (OG501) pTac inducible bacterial plasmid

Product Code: OG501R1
Product Code: OG501C1
Product Code: OG501G1

Product Description

Plasmid vector containing the inducible bacterial Tac promoter (formed by fusion of the tryptophan and lac promoters).

Plasmid Information

Product Name: pSF-Tac

Product Code: OG501

Size (bp): 3864 bp

Bacterial Antibiotic Selection: KanR

Origin and Compatibility: pUC high copy derived from pBR322

Bacterial Copy Number: 500-700 per cell

Promoter: Lac operon bacterial promoter (IPTG inducible) / Tac (IPTG inducible) bacterial promoter

Plasmid Purpose:

This is a bacterial expression plasmid containing pTAC promoter that can be regulated using the Lac repressor. The pTac promoter was created by fusing the promoter for the Lac operon with the promoter for the Tryptophan operon. This provides greater control and expression in comparison to standard Lac promoter plasmids. In order to use this plasmid you will need an E.coli cell line that expresses the LacI repressor this is a common feature of most cloning and protein expression E.coli strains.

Promoter Expression Level:

This plasmid contains the IPTG inducible promoter that was created by the fusion of the Lac promoter and the Tryptophan operon promoter. It allows inducible expression in E.coli using IPTG as the inducing agent.

Please login or sign up to view the sequence & maps
Transcription Termination:

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.

Cloning in a Gene:

This plasmid has been designed to be compatible with a range of cloning techniques. The multiple cloning site contains a range of standard commonly used restriction sites for cloning. Using these sites genes can be inserted using standard cloning methods with DNA ligase. Other methods such as ligase independent cloning (LIC) Gibson Assembly InFusionHD or Seamless GeneArt can also be used and because all of our plasmids are based on the same backbone the same method can be used for cloning into all of our catalogue vectors.

Multiple cloning site notes:

There are a few important sites within the MCS. These include the NcoI site the XbaI site and the BsgI and BseRI sites. The NcoI site contains a start codon that is immediately downstream of both a Kozak and Shine-Dalgarno ribosomal binding site. These allow for optimal positioning of genes when the start codon is placed in this location. If this is not required and you wish to use a downstream site for gene cloning you can remove the NcoI site by cleaving the plasmid with KpnI.

The XbaI site contains a stop codon. This stop codon is positioned in a specific position in relation to the BsgI and BseRI sites that are immediately downstream. When either BseRI or BsgI cleave the plasmid they produce a TA overhang from the stop codon in the XbaI site that is compatible with all of our peptide tag plasmids cut with the same sites. BseRI and BsgI sites are non-palindromic and cleave a defined number of bases away from their binding site.

Whenever we clone a gene into our multiple cloning site we always position the start and stop codon in the same positions in the MCS. If the start and ends of the genes are not compatible with NcoI and XbaI we extend the sequence to the nearest external sites but keep the start and stop codons locations consistent.

Intellectual Property Status

This product is part of our SnapFastâ„¢ plasmid range, for more information on the intellectual property status of this plasmid please click here. For more information on the terms of our licences please click here.