<h2 data-section-id="xs82dy" data-start="121" data-end="167">What are additional immortalization agents?</h2>
&nbsp;
Additional immortalization agents cover recombinant lentiviral constructs delivering genes other than TERT or SV40 large T antigen used to bypass replicative senescence in primary cells, most notably HPV-16 E6/E7 (which inactivate p53 and Rb similarly to SV40T but are derived from human papillomavirus), Bmi1 (a polycomb group protein that represses the p16/CDKN2A senescence pathway), cMyc, CDK4, and HOXA/HOXB family genes. Related entities include p16/CDKN2A pathway repression (Bmi1), keratinocyte and epithelial cell immortalization (HPV E6/E7), polycomb group signaling, and combination immortalization strategies.
&nbsp;
<h2 dir="ltr">What you will find:</h2>
&nbsp;
<ul>
<li dir="ltr" role="presentation">Lenti-HPV-16 E6/E7 degrades Rb and p53 for enhanced cell immortalization.</li>
<li dir="ltr" role="presentation">Lenti-Myc T58A &amp; Ras V12 enhance transformation and proliferation assays with high-titer mutant oncogenes&nbsp;</li>
<li dir="ltr" role="presentation">Lenti-p53 &amp; Rb siRNA Virus extends cellular longevity and targets the knockdown of tumor suppressors</li>
<li dir="ltr" role="presentation">Lenti-HOX Series (RFP Tagged) for lineage-specific expansion and includes high-titer vectors like HOXB8, HOXA9, and HOXA10 vectors.</li>
<li dir="ltr" role="presentation">EBV Virus (Wild-Type) for immortalization workflows of B-lymphocytes&nbsp;</li>
<li dir="ltr" role="presentation">Lenti-CDK4 &amp; Bmi1 Virus helps maintain proliferative capacity using cell mediators</li>
</ul>
&nbsp;
<h2 data-section-id="1acs4rs" data-start="1029" data-end="1087">How to choose additional immortalization agent products</h2>
&nbsp;
HPV E6/E7 for epithelial and keratinocyte immortalization
HPV-16 E6 and E7 proteins inactivate p53 and Rb respectively, similar in net effect to SV40 large T antigen but derived from a different viral source; E6/E7-based immortalization is particularly well-documented for keratinocytes and other epithelial cell types, and is sometimes preferred over SV40T for these lineages based on published precedent.
Bmi1 for stem and progenitor cell types
Bmi1 represses the p16/CDKN2A senescence pathway through its role in the polycomb repressive complex, and has been used to extend the proliferative capacity of hematopoietic and neural stem/progenitor cells in research settings; confirm the specific cell type has documented precedent for Bmi1-based extension before relying on it as a primary immortalization strategy.
cMyc and CDK4 as proliferation-driving factors
cMyc and CDK4 overexpression can drive proliferation and contribute to immortalization, often used in combination rather than as standalone immortalization agents; review the specific combination strategy in the source literature before ordering individual components.
E6/E7 separate vs. fused constructs
HPV E6/E7 may be delivered as separate genes or as a fused open reading frame; confirm which configuration a published protocol specifies, since this can affect relative expression levels of the two proteins.
&nbsp;
<h2 data-section-id="1fljvas" data-start="3287" data-end="3312">Specifications context</h2>
&nbsp;
Additional immortalization agent lentiviruses are typically supplied at titers around 1x10^8 TU/mL, shipped on dry ice and stored at -80&deg;C, with antibiotic or fluorescent-antibiotic fusion selection markers consistent with other immortalization lentivirus products. Pack sizes for academic labs commonly consist of small-volume aliquots sufficient for multiple transduction attempts, with constructs validated by sequencing and tested free of common contaminants.&nbsp;
This sub-category sits within MBP's cell immortalization catalog alongside TERT overexpression viruses and SV40T antigen overexpression viruses. Labs constructing custom combination vectors can also review MBP's cloning reagents. MBP's specialist team can help confirm which immortalization agent has documented precedent for a specific cell type before order placement.
<a href="https://mbpinc.net/contact-us">Contact the expert team </a>at MBP today to book high-quality immortalization vectors for your lab.

Additional Immortalization Agents

MSDS

Lentiviral Vector Amplification - Protocol

Lentivector Packaging - Protocol

Lentivirus Infection - Protocol

Cell Immortalization - Handbook

Cell Immortalization Reagents - FAQ

Lenti-Ras V12 Virus, High Titer

Unit Quantity

Application

Expression System Type

Vector Map

Note

Caution

Shipping Condition

Lenti-Rb siRNA Virus, High Titer

<h2 data-section-id="6b0hnw" data-start="102" data-end="151">What are SV40T antigen overexpression viruses?</h2>
&nbsp;
SV40T antigen overexpression viruses are recombinant lentiviral particles carrying the simian virus 40 (SV40) large T antigen gene, a hexamer protein that inactivates the p53 and retinoblastoma (Rb) tumor suppressor pathways, bypassing the senescence checkpoints that normally limit primary cell proliferation. Some constructs deliver the large T antigen alone, while others include both large and small T antigens. Related entities include p53/Rb pathway inactivation, broad cross-species immortalization (human, mouse, rat, bovine, porcine, canine), karyotype/tumorigenicity characterization (soft agar assay), and antibiotic/fluorescent selection markers.
&nbsp;
<h2 dir="ltr">What you will find:</h2>
&nbsp;
<ul>
<li dir="ltr" role="presentation">Lenti-SV40 (tsA58 Mutant) for cell proliferation with inducible control and temperature-sensitive expression</li>
<li dir="ltr" role="presentation">Lenti-SV40T (Puro/Neo/No Marker) provides stable integration with versatile selection markers of highly concentrated lentiviral stocks&nbsp;</li>
<li dir="ltr" role="presentation">Adeno-SV40 Adenovirus for transient T-antigen expression with high-efficiency adenoviral vectors</li>
<li dir="ltr" role="presentation">Retro-SV40 &amp; Retro-SV40LT for special integration in proliferating cells.</li>
<li dir="ltr" role="presentation">Lenti-SV40Tt Lentivirus: Small T and Large T antigens for improved transformation.</li>
</ul>
&nbsp;
<h2 data-section-id="ykynp3" data-start="1032" data-end="1092">How to choose SV40T antigen overexpression virus products</h2>
&nbsp;
Large T antigen alone vs. large and small T antigen
Constructs delivering large T antigen alone target p53/Rb pathway inactivation specifically, while large-and-small-T constructs include additional SV40 small T antigen activity affecting protein phosphatase 2A (PP2A) signaling; confirm which form a published protocol specifies, since the two can produce different immortalization efficiencies and phenotypes.
Species applicability
SV40 large T antigen has documented immortalization success across human, mouse, rat, bovine, porcine, and canine primary cells, making it a broadly applicable option when hTERT (human-specific) is not suitable for the target species.
Selection marker and promoter
As with TERT lentivirus, SV40T constructs are available under CMV or EF1-alpha promoters with antibiotic resistance (puromycin, hygromycin, blasticidin, neomycin/G418, zeocin) or fluorescent-antibiotic fusion markers (GFP-Bsd, RFP-Puro); select based on the target cell line's existing markers and expected culture duration.
Post-immortalization characterization
Because SV40 large T antigen inactivates tumor suppressor pathways, immortalized lines should be characterized for karyotype changes and tested by assays such as soft agar colony formation and tumorigenicity testing if downstream applications require confirmation that the line has not undergone malignant transformation.
&nbsp;
<h2 data-section-id="1fljvas" data-start="3482" data-end="3507">Specifications context</h2>
&nbsp;
SV40T antigen lentivirus is typically supplied at titers around 1x10^8 TU/mL, shipped on dry ice and stored at -80&deg;C, with constructs validated by full-length sequencing and confirmed free of common contaminants. Immortalized lines derived from SV40T transduction are commonly characterized by Western blot or immunofluorescence confirming SV40-LT protein expression, alongside marker expression comparison to the original primary cells. As of 2026, SV40 large T antigen remains the most broadly cross-species-applicable immortalization approach, often selected when hTERT (human-specific) is not an option for the target species or when faster immortalization is prioritized over preserving the original phenotype.
This sub-category sits within MBP's cell immortalization catalog alongside TERT overexpression viruses and additional immortalization agents. Labs constructing custom SV40T expression vectors can also review MBP's cloning reagents. MBP's specialist team can help confirm species applicability and vector format for a specific primary cell type before order placement.
<a href="https://mbpinc.net/contact-us">Contact the expert team </a>at MBP today to get high-quality SV40T antigen overexpression viruses.

SV40T Antigen Overexpression Viruses

Lenti-SV40 (tsA58 temperature sensitive mutant) (No Selection Marker) Lentivirus, High Titer

Lenti-SV40 (tsA58 temperature sensitive mutant) Lentivirus, High Titer

Lenti-SV40 Lentivirus, High Titer

Lenti-SV40T  (No Selection Marker) Lentivirus, High Titer

Lenti-SV40T (Neo) Lentivirus, High Titer

Lenti-SV40T (Puro) Lentivirus, High Titer

Lenti-SV40Tt Lentivirus, High Titer

<h2 dir="ltr"> What Are Lentiviral Cloning Vectors?</h2>
 The transfer plasmid is the heart of every lentiviral construct &mdash; it defines the transgene cargo, promoter driving expression, selection marker, and structural LTR elements that enable stable genomic integration. Selecting the right cloning vector backbone is the first and most consequential decision in any lentiviral project.
&nbsp;
<h2 dir="ltr">What you will find:</h2>
&nbsp;
<ul>
<li style="font-family: arial, helvetica, sans-serif;">Expression vectors featuring CMV, EF1&alpha;, PGK, and UbC promoter configurations for transgene expression studies</li>
<li>Fluorescent reporter vectors incorporating GFP, RFP, and CFP for cell tracking and visualization</li>
<li>Promoterless vectors for promoter characterization and regulatory element analysis</li>
<li>HA-tag and His-tag expression vectors for protein detection and purification workflows</li>
<li>Bicistronic and tricistronic vector systems for multi-gene expression applications</li>
<li>miRNA- and siRNA-compatible cloning vectors for RNA interference studies</li>
<li>Functional vectors including selectable-marker and HSVtk-based constructs for specialized research applications</li>
</ul>
<h2 dir="ltr"> How to Choose a Lentiviral Cloning Vector</h2>
&nbsp;
Vector Design
Expression vectors, reporter vectors, promoterless systems, tagged constructs, and multicistronic backbones are designed for different experimental objectives. Vector selection should be guided by the intended application, transgene design, and downstream analysis requirements.
Promoter Selection
Promoters influence the strength and pattern of transgene expression. Available vector configurations include CMV, EF1&alpha;, PGK, and UbC promoters, as well as promoterless backbones for studies focused on promoter activity and regulatory elements.
Reporter Requirements
Fluorescent reporters such as GFP, RFP, and CFP enable visualization of transduced cells, monitoring of expression, and assessment of transduction efficiency. Reporter selection should align with the imaging platform and experimental workflow.
Expression Configuration
Single-gene, bicistronic, and tricistronic vector designs provide different levels of flexibility for co-expression studies. Multi-cassette systems can simplify experiments requiring coordinated expression of multiple genes or reporter elements.
Insert Size Considerations
Lentiviral vectors can accommodate relatively large expression cassettes compared with several other viral delivery systems. However, larger inserts may reduce viral production efficiency and should be evaluated during vector design and validation.
<h2 dir="ltr"> Specifications Context</h2>
 Modern research lentiviral vectors are commonly designed with self-inactivating (SIN) long terminal repeats (LTRs), an important biosafety feature that reduces promoter activity within the integrated viral LTR following transduction. Many lentiviral vector systems also incorporate regulatory elements that support efficient transgene expression and vector performance. Vector architecture, promoter selection, reporter configuration, and insert size can all influence downstream cloning, viral production, and expression outcomes. Product availability reflects MBP's catalogue as of mid-2026. 
The search for reliable lentiviral cloning vectors is over. <a href="https://mbpinc.net/contact-us">Contact the expert team</a> at MBP and find the perfect match today.

Cloning Vectors

Selection-Drug Killing Curve

Lenti-Tri-cistronic Vector

Vector

<h2 dir="ltr">What Are miRNA Lentiviral Negative Controls?</h2>
 MicroRNAs (miRNAs) are approximately 22-nucleotide non-coding RNAs that regulate gene expression post-transcriptionally by binding to the 3&prime; UTR of target mRNAs, triggering mRNA degradation or translational repression via the RNA-induced silencing complex (RISC). Lentiviral delivery of miRNA expression constructs enables stable, long-term modulation of miRNA activity &mdash; essential where transient transfection approaches are insufficient.
&nbsp;
<h2 dir="ltr">What you will find:</h2>
&nbsp;
<ul>
<li dir="ltr" aria-level="1">
Control Viruses models used in miRNA overexpression studies, for negative control normalization
</li>
<li dir="ltr" aria-level="1">
Validation of 3'UTR target utilizing bioluminescent-based reporter assays.
</li>
<li dir="ltr" aria-level="1">
miRNA-Off Control Lentiviruses used to baseline microRNA knockdown effects.
</li>
<li dir="ltr" aria-level="1">
Blank 5&rsquo; UTR reporter vector optimized for gene expression normalization and translational regulation studies&nbsp;
</li>
<li dir="ltr" aria-level="1">
Reporter Stable Cell Lines models with Luciferase or GFP markers for reliable assay standardization.
</li>
</ul>
<h2 dir="ltr"> How to Choose a miRNA Negative Control</h2>
 Experiment Type Matching miRNA mimic (gain-of-function) experiments require a non-targeting miRNA mimic control. miRNA inhibitor/antagomiR (loss-of-function) experiments require a non-targeting inhibitor control. Lentiviral miRNA expression requires an empty vector or scrambled miRNA sequence. Mimic Control Design A non-targeting miRNA mimic control is a double-stranded RNA molecule resembling a mature miRNA duplex but with no significant homology to any known miRNA target in human, mouse, or rat transcriptomes &mdash; entering RISC the same way as a functional mimic. Inhibitor Control Design Non-targeting miRNA inhibitor (antagomiR) controls are single-stranded antisense sequences that enter the relevant cellular compartment without blocking any known miRNA, establishing the baseline for inhibitor-treated versus non-inhibitor comparisons. Vector Backbone for Lentiviral Delivery Stable lentiviral expression of miRNAs is used for long-term gain-of-function studies; the matched non-targeting lentiviral control must use the same promoter and vector backbone as the experimental construct to isolate sequence-specific effects. Inducible Format Availability Tet-On (doxycycline-responsive) non-targeting miRNA lentiviral controls are available for experiments requiring temporal control, used alongside inducible experimental constructs to control for doxycycline treatment itself. 
<h2 dir="ltr"> Specifications Context</h2>
 miRNA controls are designed to reflect the endogenous processing pathway of microRNAs, including Drosha and Dicer-mediated maturation before RISC loading. Because siRNA and miRNA constructs enter the RNA interference pathway differently, pathway-matched controls are important for accurate experimental interpretation. Non-targeting miRNA controls help distinguish sequence-specific effects from background effects associated with vector delivery and miRNA pathway activation. Available formats include lentiviral vectors, packaged viruses, reporter constructs, and stable cell line controls for miRNA and UTR-based studies. Product availability reflects MBP's catalogue as of mid-2026. 
&nbsp;
<a href="https://mbpinc.net/contact-us">Contact the expert team at MBP</a> and request a quote for efficient miRNA control requirements.

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