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LacSwitch II Inducible Mammalian Expression System - Details & Specifications

The ability to reversibly turn genes off and on is a powerful tool in the investigation of various genetic functions. In the Escherichia coli lactose (lac) operon, the Lac repressor binds as a homotetramer to the lac operator, blocking transcription of the lacZ gene. Physiological or synthetic inducers, such as allolactose or isopropyl ß-D-thiogalactopyranoside (IPTG) respectively, bind to the Lac repressor causing a conformational change and effectively decrease the affinity of the repressor for the operator. When the repressor is removed from the operator, transcription from the lac operon resumes.

The LacSwitch II inducible mammalian expression system utilizes an improved vector system in which several elements of the lac operon have been modified for use in eukaryotic cells for the control of gene expression. This method for inducible expression of exogenous genes in eukaryotic cells consists of a eukaryotic Lac-repressor expressing vector, pCMVLacI, and two eukaryotic lac-operator containing vectors, pOPRSVI/MCS, and pOPI3CAT, into which the gene of interest is inserted by cloning – view complete vector details. These vectors are transfected into a cultured cell line in which expression of the inserted gene is repressed until an inducer is added to the media. Upon induction, expression of the inserted gene resumes.

The LacSwitch II inducible mammalian expression system is a versatile and proven alternative to other systems. The system uses a nontoxic, fast-acting inducer, IPTG, which permits induction in 4–8 hours, partly due to the rapid transportation of IPTG into eukaryotic cells. The LacSwitch II expression system exhibits low basal expression of a luciferase reporter gene (~10–20 molecules/cell) when in the repressed state. This repression level is partially dependent on the half-life of the inserted gene.

The establishment of a highly regulated expression system in eukaryotic cells, maintained in a repressed state until induced by an exogenous stimulus, is an invaluable tool for the study of cell cycle, oncogenicity, cytogenicity, and the mechanisms of gene regulation.


For Research Use Only. Not for use in diagnostic procedures