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ATF2 Reporter Lentivirus
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GATA1 Reporter Lentivirus
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FXRE/ER2 Reporter Lentivirus
$595.00
FXRE/ER2 Reporter Lentivirus: A high-quality lentiviral reporter system designed to detect transcriptional activity mediated by the Farnesoid X Receptor (FXR), specifically the FXRα2 and FXRα4 isoforms, in mammalian cells. This reporter is constructed with tandem repeats of the FXR Response Element (FXRE) arranged as everted repeats separated by 2 nucleotides (ER2 configuration), which preferentially respond to FXRα2/4-driven transcription. FXR is a ligand-activated nuclear receptor that modulates gene expression involved in bile acid, fat, sugar, and amino acid metabolism. The FXRE/ER2 reporter lentivirus is purified by PEG precipitation and sucrose gradient centrifugation, ensuring optimal performance for transducing primary and/or thawed cells.
Have questions about this product? Need a stable cell line? Send us a form and we’ll reply the same day: Contact Us
Ultra-high concentration virus can be provided upon request in your choice of medium and volume for in vivo injection. We can provide custom reporter genes (such as SEAP, YFP, secreted Gaussia Luc, Renilla Luc, etc.) and selection markers (hygromycin, bleomycin, etc.) upon request.
Available Options:
Specifications
Details
| LTV-0130 | |
| FXR signaling pathway | |
| FXRE arranged as everted repeats separated by 2 nucleotides (ER2 configuration) | |
| Monitor FXRα2/4 activity in mammalian cells, screen for activators or inhibitors of FXR-mediated transcriptional activity, and investigate FXR isoform-specific functions in bile acid, lipid, and glucose metabolism. This reporter is preferentially responsive to FXRα2 and FXRα4 isoforms. The fluorescent reporter provides real-time analysis using flow cytometry, fluorescence microscopy, or similar assays. | |
| Human/mouse |
Product Data
Figure 1. GFP Reporter activation of FXRE/ER2-TAG-Puro. HEK293FT cells were co-transfected with FXRE/ER2-TAG-Puro construct plus cDNA encoding FXRα2 (with RFP downstream of the gene, separated by P2A) for 36 h before acquiring fluorescent microscopy images. This product is supplied as pre-packaged lentiviral particles with your choice of reporter and selection marker. Featured cDNA expression vectors are also available upon request. For more information, please email info@lipexogen.com.
Have questions about this product? Send us a form and we’ll reply the same day: Contact Us
Vector Diagram
Background
The Farnesoid X Receptor (FXR), encoded by a single gene in both humans and mice, exists in four isoforms (FXRα1–α4) generated through two promoters and alternative splicing. While all isoforms activate canonical FXRE/IR1 reporters evenly, only FXRα2 and FXRα4 exhibit stronger activation of the FXRE/ER2 configuration. This selectivity provides a more precise readout for isoform-specific transcriptional responses.
FXR plays a central role in regulating genes involved in bile acid synthesis, lipid metabolism, and glucose homeostasis. Notably, FXRα2—but not FXRα1—enhances fatty acid handling and insulin sensitivity, with both isoforms contributing to reduced hepatic lipid accumulation via distinct mechanisms. FXR expression and splicing are dynamically influenced by physiological states such as fasting and physical exercise. The FXRE/ER2 reporter provides a powerful tool for dissecting isoform-specific transcriptional activity, facilitating discovery in metabolism, endocrine signaling, and nuclear receptor biology.
Recommended Controls
Without proper controls, your data is meaningless.
Controls aren’t just an accessory—they’re the foundation for interpreting reporter activity with confidence. These recommended lentiviral controls help you validate signal strength, confirm successful transduction, and distinguish true activation from background noise. Based on how often we see researchers wishing they’d included them upfront, we’ve made this guidance part of the product page—to help you plan smarter and troubleshoot less.
You’ll find the recommended control options in the table below, each linking to their respective product page for more information.
| Control Type | Description | Product Page |
|---|---|---|
| Negative Control | Minimal promoter lentivirus used to assess background signal and baseline reporter activity. | View Product |
| Positive Control | Constitutive expression control to confirm reporter expression and optimize transduction. | View Product |
| Renilla Luciferase Internal Control | Luciferase-based internal control for signal normalization and dual-reporter assays. | View Product |
Custom Orders
If you require a modification to one of our products, such as a change in reporter or other vector component, please contact us. Examples of customization options are shown in the table below. Feel free to request something not in the table.
| Reporters (Expressed by pathway activation) | Options |
|---|---|
| Fluorescent | GFP, RFP, BFP2 |
| Luminescent | FLuc, RLuc, secreted GLuc, red FLuc |
| Enzymatic | SEAP, β-Lactamase |
| Degradable | d2GFP, d2RFP |
| Dual | GFP or RFP + FLuc |
| Selection Markers (Constitutively expressed) | Options |
| Drug Resistance | Puro, BSD, Hygromycin, Bleomycin |
| Fluorescent | GFP, RFP, BFP2, GFP-P2A-Puro/BSD, RFP-P2A-Puro/BSD |
Additional Custom Service Options
- Send us your cells and we can establish a stable reporter cell line for you using this product. Learn more.
- ORF cDNA plasmids featured in the product figures are available upon request.
- Ultra-high concentration virus can be provided upon request in your choice of medium and volume (i.e. for in vivo applications).
Additional Information
Additional Information
Key Advantages of LipExoGen TF Reporter Lentiviruses
1. Ultra-Sensitive Detection
Our reporters are built on a next-gen vector system that amplifies pathway-specific signals using tandem DNA response elements and a synergistic enhancer design. The result? Exceptional sensitivity with low background—perfect for detecting subtle activation in human or mouse cells.
2. Fast & Reliable Stable Cell Line Creation
Each batch is ultra-purified and high-titer, enabling efficient transduction even in hard-to-transfect cells like primary or freeze-thawed lines. Puromycin or blasticidin selection makes stable line generation fast and seamless.
3. Real-Time Discovery with Live Cell Fluorescence
Visualize pathway or transcription factor activity directly under a microscope—no luciferase assays or complex protocols required. See what’s happening in real time and catch unexpected results the easy way.
4. Flow-Ready Versatility
Need more quantitative data? Our fluorescent reporters work beautifully with flow cytometry, giving you flexibility to scale up, quantify, and analyze results however your lab runs.
5. Best-in-Class Value
We develop and optimize our lentiviral vectors in-house—so you get top-tier performance without the bloated cost. High sensitivity, reproducibility, and affordability? That’s our standard.
Selecting Proper Controls
Selecting Proper Controls
Including the proper controls is essential when using our reporter lentiviruses. Controls aren’t just helpful—they’re a fundamental part of experimental design and scientific rigor. Every week, we get emails from users who didn’t purchase controls and are now struggling to interpret weak signals, inconsistent activation, or no response at all. At that point, we can’t realistically help them. Without controls, we have no way to distinguish whether the issue is transduction, stimulus conditions, reporter activity, or cell health. You’re flying blind.
Whether it’s your first time working with lentivirus or you’re setting up a new assay, controls provide the baseline you need to validate your experiment. Positive controls confirm that activation is possible under the right conditions. Negative controls ensure background signal is accounted for. Together, they give you the power to troubleshoot confidently and avoid wasted time, money, and effort.
This isn’t just about convenience—it’s about producing data that actually means something. If you’re unsure how the product works, if you’re exploring a new pathway, or if you’re switching cell types, controls are your safety net. They anchor your results in reality.
Description of Various Controls and Their Purposes
I. The Actual TF Reporter
Cat. No.: Various
Purpose: Experimental. This is the actual reporter that you will use to test the transcriptional activity of the indicated response elements in your experimental conditions. Example: test if a condition results in activation or inhibition of NFκB transcriptional activity.
Explanation of components:
Selection: Refers to the drug selection marker gene that is used to allow you to select the transduced cells and make a stable cell line. Currently you get 2 options, either puro or BSD.
Enhancer: This refers to an optimized minimal enhancer from the human CMV promoter. It is present in all of our TF Reporter constructs and functions by amplifying the reporter transcription driven by specific TF binding to response elements and the minimal TATA promoter.
TF Binding: Refers to the specific transcriptional response elements that are present to allow pathway or TF specific activation of the reporter. They are generally arranged as tandem repeats and the number of repeats varies depending on the product.
TATA: Minimal TATA promoter. Alone, it is insufficient to drive strong transcription of the reporter. It works together with the TF-bound response elements to drive the reporter expression when the specific signal pathway or TF is transcriptionally active.
Reporter: The fluorescent or luminescent reporter that is used to readout the pathway or TF activity in the transduced cells. Currently you can choose GFP, RFP, or Firefly Luciferase (FLuc).
II. Controls
Purpose: Establish a frame of reference for “positive reporter signal” that is independent of the pathway or TF-specific transcriptional response elements. The construct is organized the same as the actual TF reporters, except that a synthetic “constitutively active” TRE sequence is used to drive reporter activation in the cells. The reporter signal in the resultant cells can be used as a positive control to gauge whether the transduction conditions need to be optimized or if your particular test conditions are insufficient to activate the actual TF reporter.
Example 1: You are trying a specific ligand to induce the activity of your TF reporter, and not seeing much reporter activation. The positive control can help you determine if this is an issue with your transduction or if the ligand you selected is unable to activate the reporter. You may need to troubleshoot the ligand, add another ligand, co-transfect the cells with another gene, or something else.
Example 2: You are testing the inhibitory effect of your compound on a specific signaling pathway and see that it produces good inhibition. You can use the reporter positive control cells to confirm the effect of the compound is specific to that signaling pathway, not an off-target effect such as broad inhibition of transcription or translation.
How to use: Transduce a separate batch of cells (not the same ones that will receive the actual TF reporter). The reporter positive control should have the same selection marker and reporter as the actual TF reporter you are using to assay the desired transcriptional activity. This ensures you can control for any impact of the drug selection. Treat the transduced cells the same way as the ones that were transduced with the TF reporter. Use the reporter signal you observe to get an idea what reporter activation should look like in your cells.
Purpose: Establish a baseline for any background reporter activity.
How to use: Transduce a separate batch of cells (not the same ones that will receive the actual TF reporter). The reporter negative control should have the same selection marker and reporter as the actual TF reporter you are using to assay the desired transcriptional activity. This ensures you can control for any impact of the drug selection. Treat the transduced cells the same way as the ones that were transduced with the TF reporter. Any reporter activation or inhibition you observe represents the basal level (independent of transcriptional response elements).
RLuc Internal Control (Constitutive)
Purpose: Establish a frame of reference for “positive reporter signal” that is independent of the pathway or TF-specific transcriptional response elements. The advantage of the RLuc internal control is that it can be used in the same cells that receive the actual TF reporter construct driving Firefly luciferase. Thus, it can be in dual luciferase assays. The construct is organized the same as the actual TF reporters, except that a synthetic “constitutively active” TRE sequence is used to drive reporter activation in the cells. The reporter signal in the resultant cells can be used as a positive control to identify well-to-well variations since the Renilla luciferase can be detected separately from Firefly luciferase in the same batch of cells.
Example 1: You are trying a specific ligand to induce the activity of your TF reporter, and not seeing much Firefly luciferase reporter activation. If Renilla luc is also not being detected, it could indicate an issue with your cells, transduction/selection conditions, the instrument, or specific reagents being used. If you can detect RLuc but not FLuc, then it likely means the effect is pathway or TF-specific based on the TF reporter you are using. Note: to rule out reagent- or equipment-specific issues related to FLuc but not RLuc, you would need to transduce a separate batch of cells with Reporter Positive Control (LTV-0072) with FLuc as the reporter. The positive control can help you determine if this is an issue with your transduction or if the ligand you selected is unable to activate the reporter. You may need to troubleshoot the ligand, add another ligand, co-transfect the cells with another gene, or something else.
Example 2: You are testing the inhibitory effect of your compound on a specific signaling pathway and see that it produces good inhibition. You can use the constitutive RLuc internal control to verify that the effect of the compound is specific to that signaling pathway, not an off-target effect such as broad inhibition of transcription or translation.
How to use: Transduce the same batch of cells that will receive or already received the actual TF reporter. The RLuc Internal Control (Constitutive) should NOT have the same selection marker as the actual TF reporter you are using to assay the desired transcriptional activity. For example, if the actual TF reporter is using puro for selection, then the RLuc internal control should use blasticidin (BSD) and vice versa. This ensures you can select the same cells twice, once for the actual TF reporter, and again for the internal control. We strongly recommend that this be performed in two separate transductions. You should transduce the cells with one of the lentiviruses first, select the transduced cells, and let them grow up and completely recover before proceeding to the next round of transduction and selection with the second lentivirus. Details can be found in our transduction protocol which comes with each product and is also available under a different tab on this page.
RLuc Internal Control (Minimal)
Purpose: Establish a baseline for any background reporter activity in the same cells that contain the actual TF reporter construct. The advantage of the RLuc Internal Control is that it can be used in the same cells that receive the actual TF reporter construct driving Firefly luciferase. Thus, it can be used in dual luciferase assays. The construct is organized the same as the actual TF reporters, except that there are no transcriptional response elements to drive the expression of RLuc. Thus, any RLuc signal that is produced under your experimental conditions represents the basal activity of the construct independent of the transcriptional response elements (minimal TATA and upstream enhancer). This is useful in experiments where you are trying to study the reporter activation and need know the background level in dual-luciferase assays.
How to use: Transduce the same batch of cells that will receive or already received the actual TF reporter. The RLuc Internal Control (Minimal) should NOT have the same selection marker as the actual TF reporter you are using to assay the desired transcriptional activity. For example, if the actual TF reporter is using puro for selection, then the RLuc internal control should use blasticidin (BSD), and vice versa. This ensures you can select the same cells twice, once for the actual TF reporter, and again for the internal control. We strongly recommend that this be performed in two separate transductions. You should transduce the cells with one of the lentiviruses first, select the transduced cells, and let them grow up and completely recover before proceeding to the next round of transduction and selection with the second lentivirus. Details can be found in our transduction protocol which comes with each product and is also available under a different tab on this page.
Lentiviral Transduction Protocol
MSDS
Frequently Asked Questions
Frequently Asked Questions
1. Can I purchase the plasmid for this product?
No. Our TF reporters are only available as high-titer lentiviral particles. This ensures efficient delivery and consistent performance. If you’re looking for plasmid-based gene products, check our cDNA or shRNA collections.
2. What reporter options are available?
Each TF reporter is offered in several formats:
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GFP or RFP (for fluorescence imaging and flow cytometry)
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Firefly Luciferase (for luminescent plate-based assays)
3. What titer is the virus? Can I use it in primary or freeze-thawed cells?
Each vial contains a functional titer, determined by transducing HEK293 cells under standardized conditions—not a concentration or particle count. GFP and RFP reporters contain at least 5×10⁶ TU per vial, while Firefly luciferase (FLuc) reporters contain 2×10⁶ TU per vial. All products are PEG-purified and sucrose gradient-concentrated, making them ideal for transducing even difficult cell types, including primary and freeze-thawed cells.
4. Can I use this product to generate stable cell lines?
Yes. Each construct includes an antibiotic resistance gene (puromycin or blasticidin), allowing straightforward generation of stable lines.
5. Do I need to purchase controls?
Yes. Without proper controls, your data is meaningless. A baseline is essential for interpreting results and assessing reporter activation. Controls are fundamental for data comparison, transduction assessment, and scientific rigor.
See the control table on this page for options.
6. What species are compatible with this reporter?
Designed for human and mouse cells. May work in other mammalian species, but only validated in human/mouse lines.
7. Can I request a different reporter or selection marker?
Yes. We support custom orders. See the “Custom Orders” section or contact us for available combinations.
8. What’s the best way to read out reporter activation?
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GFP/RFP: Use fluorescence microscopy, flow cytometry or a fluorescence plate reader.
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Luciferase: Use commercial assay kits like Promega’s Dual-Luciferase® paired with a luminescence plate reader (injectors are not necessary).
9. Are these replication-incompetent lentiviral particles?
Yes. We use a third-generation packaging system with multiple safeguards to prevent generation of replication-competent virus.
10. What MOI should I use?
We do not recommend a specific MOI. It depends on your cell type and assay conditions. Refer to the Lentiviral Transduction Protocol tab for guidance. We strongly recommend a titration to determine optimal conditions.
11. Can I infect stem cells with this product?
Yes. Many customers have successfully transduced stem cells with our lentiviral reporters.
12. Can you share the construct sequence?
No. Our vector sequences are proprietary. However, if you have a specific motif or sequence in mind, we can confirm whether it’s the same or similar. For custom elements, we offer a premium service.
13. I’m not seeing fluorescence, but my cells express the TF of interest.
Expression isn’t enough. The TF must be active, nuclear-localized, and often part of a protein complex. These factors vary by cell type. Just because the TF is present doesn’t mean it’s doing anything. If you’re unsure, controls and functional validation are key.
14. My cells all died after puromycin selection.
Start with a lower dose (0.5–1 μg/mL) for 3 days post-transduction before increasing to full strength. It can take time for antibiotic resistance to fully express. If you’re struggling to establish a stable line, we also offer cell line engineering services, which is especially helpful for customers with limited hands-on experience.
15. How much virus is in one vial?
Each vial contains ~380 μL of concentrated virus. The titer and total TU are printed on the vial and shown in the product specs.
16. I see weak signal. Is it real?
Maybe. Weak reporters may still be real—but background is always a factor. That’s what the negative control is for. If your signal isn’t clearly distinguishable, don’t guess—compare.