Cell Immortalization

<h2 data-section-id="6b0hnw" data-start="102" data-end="151">What are SV40T antigen overexpression viruses?</h2>
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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.
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<h2 dir="ltr">What you will find:</h2>
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<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>
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<h2 data-section-id="ykynp3" data-start="1032" data-end="1092">How to choose SV40T antigen overexpression virus products</h2>
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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.
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<h2 data-section-id="1fljvas" data-start="3482" data-end="3507">Specifications context</h2>
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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

MSDS

Lentiviral Vector Amplification - Protocol

Lentivector Packaging - Protocol

Lentivirus Infection - Protocol

Cell Immortalization - Handbook

Cell Immortalization Reagents - FAQ

Adeno-SV40 Adenovirus

Unit Quantity

Description

Application

Expression System Type

Vector Map

Note

Caution

Shipping Condition

<h2 data-section-id="1vscfio" data-start="222" data-end="262">What are TERT overexpression viruses?</h2>
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TERT overexpression viruses are recombinant lentiviral (or in some cases retroviral) particles carrying the human telomerase reverse transcriptase (hTERT) gene under a constitutive promoter, designed to extend telomere length and bypass replicative senescence in primary cells. Related entities include telomere maintenance, replicative senescence, population doubling limits, EF1-alpha and CMV promoters, and antibiotic/fluorescent selection markers (puromycin, hygromycin, GFP-Puro).
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<h2 dir="ltr">What you will find:</h2>
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<ul>
<li dir="ltr" role="presentation">Adeno-hTERT Antisense used in cancer research for inhibition of telomerase activity&nbsp;</li>
<li dir="ltr" role="presentation">Lenti-hTERT Virus (High Titer) used as a standard tool for efficient immortalization of primary cells&nbsp;</li>
<li dir="ltr" role="presentation">Lenti-EF1a-hTERT Virus uses the EF1a promoter for reliable, long-term expression.</li>
<li dir="ltr" role="presentation">Adeno-hTERT is used in transient TERT expression for high-efficiency adenoviral delivery</li>
<li dir="ltr" role="presentation">Lenti-hTERT is used as a streamlined vector for specialized genetic engineering.</li>
<li dir="ltr" role="presentation">Lenti-hTERT-2A-CDK4 Virus co-expression for complex cell types like myogenic cells.</li>
<li dir="ltr" role="presentation">Lenti-EF1a-hTERT-Hygro Virus for precise metabolic selection featuring hygromycin resistance&nbsp;</li>
<li dir="ltr" role="presentation">Lenti-hTERT-Neo Virus for stable generation of cell lines, includes neomycin/G418 resistance&nbsp;</li>
</ul>
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<h2 data-section-id="t86qiz" data-start="932" data-end="983">How to choose TERT overexpression virus products</h2>
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Promoter selection
EF1-alpha promoter constructs are often preferred for primary cells where CMV promoter silencing over extended culture is a concern, though CMV-driven constructs offer strong initial expression; the choice may depend on the expected culture duration and cell type-specific promoter activity.
Selection marker type
Antibiotic resistance markers (puromycin, hygromycin, neomycin/G418, blasticidin) allow selection of stably transduced populations by drug treatment, while fluorescent-antibiotic fusion markers (e.g., GFP-Puro) additionally allow visual confirmation of expression and flow sorting; confirm the target cell line's existing markers don't conflict.
Titer and transduction efficiency
hTERT lentivirus is typically supplied at titers around 1x10^8 TU/mL; transduction efficiency depends on the target cell type's susceptibility to lentiviral infection, and some difficult-to-transduce primary cells may require optimization of multiplicity of infection (MOI) or use of transduction enhancers.
Species considerations
hTERT is human-specific; for non-human primary cells, confirm whether a species-matched TERT ortholog is available or whether SV40 large T antigen (with broader documented cross-species activity) is a more appropriate alternative for the target species.
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<h2 data-section-id="1fljvas" data-start="3151" data-end="3176">Specifications context</h2>
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TERT overexpression lentivirus is typically supplied at approximately 1x10^8 TU/mL in small-volume vials (e.g., 25 microliters per vial), shipped on dry ice and stored at -80&deg;C, with constructs validated by full-length sequencing and confirmed free of mycoplasma and common contaminants. Stable transduction and selection typically take 1-2 weeks before characterization, with full confirmation of telomere extension and extended proliferative capacity assessed over subsequent passages. As of 2026, hTERT lentivirus remains a standard tool for generating immortalized cell lines that retain much of the original primary cell's phenotype, distinguishing it from the more transformation-prone SV40 large T antigen approach.
This sub-category sits within MBP's cell immortalization catalog alongside SV40T antigen overexpression viruses and additional immortalization agents. Labs building custom expression constructs can also review MBP's cloning reagents for vector and competent cell options. MBP's specialist team can help confirm promoter and selection marker choices for a specific primary cell type before order placement.
Browse our collection and <a href="https://mbpinc.net/contact-us">contact the expert team at MBP</a> today to find premium-quality TERT viral vectors for your lab.&nbsp;

TERT Overexpression Viruses

Adenovirus MSDS

Lentivirus MSDS

Adeno-hTERT

Adeno-hTERT Antisense

<h2 data-section-id="xs82dy" data-start="121" data-end="167">What are additional immortalization agents?</h2>
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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.
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<h2 dir="ltr">What you will find:</h2>
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<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>
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<h2 data-section-id="1acs4rs" data-start="1029" data-end="1087">How to choose additional immortalization agent products</h2>
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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.
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<h2 data-section-id="1fljvas" data-start="3287" data-end="3312">Specifications context</h2>
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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.