Cloning & Expression Systems
Your transgene output switches on with a small-molecule trigger such as cumate or doxycycline, instead of relying on constitutive promoters alone.
The cumate-CymR system uses the CuO operator paired with the CymR repressor. This system is tightly repressed at baseline and is activated by adding cumate to the culture medium. Inducible vectors are available in lentiviral and non-viral formats, including transposon-based and episomal configurations. This gives you the choice of stable integration or long-term episomal expression within the same inducible framework.
For subcellular localisation studies, a library of vectors places your fusion protein at defined compartments. These include the cytoplasm, nucleus, mitochondria, and exosome pathway. Tet-based inducible cell lines with doxycycline-controlled expression are available off the shelf for your downstream reporter validation.
Constitutive mammalian expression vectors come with a variety of N- and C-terminal tags, including DDK, His, GFP, and HA. These give you a characterised backbone for transient or stable expression when you do not need induction.
1. Inducible vs. constitutive. If you need timing control, choose a CuO-CymR or Tet-based system. If you just need steady expression, constitutive mammalian expression vectors with selectable tag configurations give you consistent output without an inducer.
2. Delivery format for inducible vectors. For stable integration, choose lentiviral CuO-CymR transfer vectors paired with packaging plasmids for your project. Alternatively, transposon-based cumate-inducible donor vectors work with the matching transposase. For episomal persistence without integration, use an enhanced episomal inducible vector format.
3. Subcellular targeting. When you study protein localisation, a subcellular localisation vector library covers cytoplasmic, nuclear, mitochondrial, and exosomal compartments as pre-built fusion constructs, matched to your study.
4. Tag selection for detection or purification. Constitutive expression vectors are available with DDK (FLAG), His, GFP, and HA tags at either terminus. The tag matches your downstream assay, whether pull-down, immunofluorescence, or flow cytometry.
Parent category: protein expression systems
Dose-response and toxicity studies
Inducible systems let you titrate output by adjusting inducer concentration, enabling dose-response curves for toxic overexpression targets.
Temporal control of gene activation
Adding or removing inducer at defined time points helps dissect signalling cascades, study cell cycle entry, or model developmental activation events in your system.
Subcellular localisation studies
Pre-built vectors target the cytoplasm, nucleus, mitochondria and exosomes. Fluorescent protein vectors help you assess compartment effects on function.
Recombinant protein production
Constitutive mammalian vectors, with defined promoters and epitope tags, support production of your glycosylated or modified proteins.
Stable and inducible cell line generation
Lentiviral and transposon-based delivery integrate the cassette for long-term studies. Lentiviral systems pair vectors with packaging plasmids.
Epitope-tagged detection and pull-down
DDK, His, GFP and HA tags support immunoprecipitation, Western blot or flow cytometry. Primary antibodies against common tags complete the workflow.
Constitutive promoters, such as CMV and EF1a, drive continuous transcription regardless of culture conditions. Inducible promoters stay silent until an external stimulus, such as doxycycline (Tet system) or cumate (CuO-CymR system), is added.
Inducible systems give you temporal and dose control of transgene expression. This matters when continuous overexpression is toxic, or when the timing of activation is part of the experimental question.
The CuO-CymR system uses the CymR repressor protein. CymR binds to the cumate operator (CuO) sequence in the promoter and blocks transcription. When you add cumate to the medium, it binds CymR and causes it to leave CuO, so transcription can proceed.
Cumate is non-toxic at the concentrations used. It does not cross-activate other signalling pathways, which makes it an orthogonal induction system.
Tag choice depends on the downstream assay. FLAG and HA tags are small peptides that do not disrupt most protein structures. They have well-validated antibodies for immunoprecipitation and Western blot. His-tags allow single-step metal affinity purification. GFP and other fluorescent protein fusions allow direct visualisation without secondary detection.
Test N-terminal or C-terminal placement when the tag could interfere with the protein active site or signal peptide.
Product catalogs
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