STELLARTAQ DNA POLYMERASE
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PCR. Uninhibited.
StellarTaq™ DNA Polymerase (DNAP) is engineered for extreme inhibitor tolerance, speed, and specificity. The polymerase catalyzes 5′ → 3′ DNA synthesis, has 5′ → 3′ exonuclease activity, and is deficient in 3′ → 5′ exonuclease activity making it suitable for probe digestion. It amplifies uracil-containing templates, incorporates modified bases, and performs A-tailing on DNA products. Available in hot start, non-hot start, and glycerol-free formats.
Key Features and Benefits
- Extreme inhibitor tolerance offers robust amplification across a range of clinical sample types, including urine, blood, sputum and bile
- High speed enables fast PCR applications
- Hot start mechanism ensures high specificity
- Custom formats, including high concentrate and glycerol-free, support lyophilization
Applications
- Pathogen detection, including infectious diseases
- Fast PCR
- RT-qPCR
- PCR amplification of DNA fragments ≤ 5 kb
- Probe and intercalating dye-based qPCR
- PCR applications where biological inhibitors are present and specificity is important
Properties
Unit definition: One unit of StellarTaq DNA Polymerase incorporates 16 nmol of dNTPs into a DNA template in 30 minutes at 72°C
Reaction conditions* (materials not included in this kit):
- 20 mM Tris-HCl, pH 8.3
- 100 mM KCl
- 0.004% Tween 20
* Baseline reaction condition, optimization is required. See technical guide for more information.
Enzyme storage buffer:
- Standard: 50 mM Tris-HCl, pH 7.5, 100 mM KCl, 0.1 mM EDTA, 50% Glycerol, 0.05% Tween 20
- Glycerol-free: 50 mM Tris-HCl, pH 7.5, 300 mM KCl, 0.05% Tween 20
Key Performance Data
Extreme inhibitor tolerance
Inhibitors – ubiquitous in biological samples – can interfere with amplification, leading to inaccurate results and false negatives. Using an inhibitor-tolerant polymerase ensures reliable amplification even in the presence of challenging substances found in clinically relevant samples, essential for accurate pathogen detection. StellarTaq™ delivers leading inhibitor-tolerance for accurate and reproducible results every time.
Figure 1A. Robust amplification ... MORE
Figure 1B. Robust amplification ... MORE
Figure 1C. Robust amplification ... MORE
Extreme inhibitor tolerance
Figure 1A. Robust amplification in the presence of urine. StellarTaq DNA Polymerase (DNAP), wild-type Taq DNAP, and other commercially available engineered Taq DNAPs (Suppliers T and R) were evaluated in probe-based qPCR. A 131 bp region of the SARS-CoV-2 ORF1ab gene was amplified from 20,000 copies of target DNA in the presence of increasing urine concentrations. ΔCq values were calculated: Cq (with inhibitor) - Cq (without inhibitor) and are displayed as a heat map where a lower ΔCq indicates increased DNA yield and inhibitor tolerance. StellarTaq had the highest inhibitor tolerance enabling accurate qPCR results on crude sample types.
Figure 1B. Robust amplification in the presence of saliva. StellarTaq DNA Polymerase (DNAP), wild-type Taq DNAP, and other commercially available engineered Taq DNAPs (Suppliers T and R) were evaluated in probe-based qPCR. A 131 bp region of the SARS-CoV-2 ORF1ab gene was amplified from 20,000 copies of target DNA in the presence of increasing saliva concentrations. ΔCq values were calculated: Cq (with inhibitor) - Cq (without inhibitor) and are displayed as a heat map where a lower ΔCq indicates increased DNA yield and inhibitor tolerance. StellarTaq had the highest inhibitor tolerance enabling accurate qPCR results on crude sample types.
Figure 1C. Robust amplification in the presence of blood. StellarTaq DNA Polymerase (DNAP), wild-type Taq DNAP, and other commercially available engineered Taq DNAPs (Suppliers T and R) were evaluated in probe-based qPCR. A 131 bp region of the SARS-CoV-2 ORF1ab gene was amplified from 20,000 copies of target DNA in the presence of increasing blood concentrations. ΔCq values were calculated: Cq (with inhibitor) - Cq (without inhibitor) and are displayed as a heat map where a lower ΔCq indicates increased DNA yield and inhibitor tolerance. StellarTaq had the highest inhibitor tolerance enabling accurate qPCR results on crude sample types.
Enable fast PCR
Fast PCR is essential for pathogen detection, providing rapid identification of contaminating bacteria and viruses. Its reduced reaction times enhance workflow efficiency, boost lab throughput, and enable timely decision-making.


Figure 2. Get rapid results ... MORE
Enable fast PCR


Figure 2. Get rapid results. StellarTaq DNAP, wild-type Taq DNAP and other commercially available engineered Taq DNAPs (Suppliers T and R) were evaluated for polymerization speed by assessing extension of a pre-primed, ssDNA template at 72°C. Relative polymerization speed was measured over time by monitoring the fluorescence of an intercalating dye. StellarTaq had the fastest polymerization speed which enables faster workflows and ultra-fast PCR.
Amplify in the presence of reverse transcriptase
For challenging or crude samples in viral pathogen detection, increasing reverse transcriptase concentration can boost yield and sensitivity — but too much can inhibit PCR efficiency. StellarTaq is designed to tolerate a wider range of RT concentrations, ensuring consistent, high-performance qPCR without compromise.
Figure 3A. Efficient amplification of SARS-CoV-2 ... MORE
Figure 3B. Efficient amplification of SARS-CoV-2 ... MORE
Amplify in the presence of reverse transcriptase
Figure 3A. Efficient amplification of SARS-CoV-2 N in the presence of reverse transcriptase. The impact of increasing reverse transcriptase concentration (StellarScript® HT+) was assessed for StellarTaq DNAP and wild-type Taq DNAP using a one-step multiplex RT-qPCR assay amplifying a 67 bp region of SARS-CoV-2 N from 10 copies of target RNA. 1 ng of Universal Human Reference RNA was added to mimic a biological sample. StellarTaq had increased yield and sensitivity at higher concentrations of StellarScript HT+.
Figure 3B. Efficient amplification of SARS-CoV-2 ORF1ab in the presence of reverse transcriptase. The impact of increasing reverse transcriptase concentration (StellarScript® HT+) was assessed for StellarTaq DNAP and wild-type Taq DNAP using a one-step multiplex RT-qPCR assay amplifying a 131 bp region of SARS-CoV-2 ORF1ab from 10 copies of target RNA. 1 ng of Universal Human Reference RNA was added to mimic a biological sample. StellarTaq had increased yield and sensitivity at higher concentrations of StellarScript HT+.
BROCHURES
Precision Enzymes and Proteins Brochure
Custom Genomic Solutions Enzymes MDx DNA Polymerase I Equinox Library Amplification Equinox Uracil-Tolerant Library Amplification phi29 DNAP RNase Inhibitor RNase H StellarScript RT StellarScript HT RT StellarScript HT+ RT StellarTaq DNA Polymerase T4 DNA Ligase T4 DNAP T4 Polynucleotide Kinase T4 Gene 32 Protein Taq DNAPWatchmaker Genomics offers a portfolio of precision-engineered enzymes and proteins, designed to meet the demands of high-stringency applications. We provide tailored services such as custom fills, formats, packaging, and labeling to accommodate unique specifications.
StellarTaq DNA Polymerase Brochure
Pathogen Detection PCR/qPCR RT-PCR/RT-qPCR DNA Blood Saliva/buccal Urine Enzymes MDx StellarTaq DNA PolymeraseThis brochure highlights the capabilities of StellarTaq DNA polymerase with respect to polymerization speed and inhibitor tolerance making it an excellent option for pathogen detection platforms and assays.
Custom Genomic Solutions Brochure
Custom Genomic Solutions Isothermal Amplification Pathogen Detection PCR/qPCR Rolling Circle Amplification RT-PCR/RT-qPCR Enzymes MDx Equinox Library Amplification Equinox Uracil-Tolerant Library Amplification phi29 DNAP Recombinase Polymerase Amplification (RPA) RNase Inhibitor RNase H StellarScript RT StellarScript HT RT StellarScript HT+ RT StellarTaq DNA Polymerase Bsu DNA Polymerase, Large Fragment T4 DNA Ligase T4 DNAP T4 Polynucleotide Kinase T4 Gene 32 Protein Taq DNAP T4 UvsX DNA Recombinase T4 UvsY ProteinWhether you need small-scale modifications or a fully custom solution, Watchmaker’s flexible model ensures you get exactly what you need — with speed, simplicity, and scientific precision.
VIDEOS
Built for the frontline: Breaking POC barriers through protein engineering
CNV Calling Isothermal Amplification Methyl Sequencing PCR/qPCR RT-PCR/RT-qPCR SNV/SNP/InDel Detection Variant Calling DNA RNA Blood Plasma/cfDNA Saliva/buccal Urine Enzymes MDx Recombinase Polymerase Amplification (RPA) StellarTaq DNA PolymeraseThis video is part of the Watchmaker MDx workshop at AMP 2025, and features Trey Foskett explaining the science behind the Watchmaker protein engineering platform, and how this generates enzymes with improved performance.
POSTERS
Engineered reverse transcriptases and Taq DNA polymerases deliver robust yield in the presence of clinically relevant inhibitors
PCR/qPCR RT-PCR/RT-qPCR DNA RNA Enzymes MDx StellarScript RT StellarScript HT RT StellarScript HT+ RT StellarTaq DNA PolymeraseThis poster discusses the engineering of reverse transcriptases and Taq DNA polymerases to enhance thermostability and inhibitor tolerance, addressing challenges in molecular diagnostics. The engineered enzymes, such as StellarScript HT+ and aCat174 Taq DNA polymerase, demonstrate improved performance in the presence of common inhibitors, making them suitable for applications like RT-qPCR, RNA sequencing, and PCR amplification from challenging samples.
The use of engineered reverse transcriptase and Taq DNA polymerase variants for improved activity and inhibitor tolerance in POC MDx applications
PCR/qPCR RT-PCR/RT-qPCR DNA RNA Blood Saliva/buccal Urine MDx StellarScript HT+ RT StellarTaq DNA PolymeraseThis poster presents data demonstrating the inhibitor tolerance of StellarTaq, including sample types such as urine, saliva and blood, purification contaminants such as heparin and DMSO, and reverse transcriptase.
PROTOCOLS
StellarTaq DNA Polymerase Technical Guide
Enzymes MDx StellarTaq DNA PolymeraseThis protocol details the use of StellarTaq™ DNA Polymerase - engineered for speed, inhibitor tolerance, and specificity for applications like pathogen detection, qPCR, and RT-qPCR. It also describes its ability to amplify uracil-containing templates, incorporate modified bases, and perform A-tailing on DNA products.
| CONFIGURATION | |
|---|---|
| Kit contents (one of the following) | StellarTaq™ Hot Start DNA Polymerase (5 U/µL) StellarTaq Hot Start DNA Polymerase - Glycerol-Free (30 U/uL or 140 U/µL) StellarTaq DNA Polymerase (5 U/µl) StellarTaq DNA Polymerase - Glycerol-Free (140 U/µL) |
| Unit definition | One unit of StellarTaq DNA Polymerase incorporates 16 nmol of dNTPs into a DNA template in 30 minutes at 72°C. |
| Enzyme storage buffer formulation | Standard: 50 mM Tris-HCl, pH 7.5, 100 mM KCl, 0.1 mM EDTA, 50% Glycerol, 0.05% Tween 20 Glycerol-free: 50 mM Tris-HCl, pH 7.5, 300 mM KCl, 0.05% Tween 20 |
| QUALITY CONTROL | |
|---|---|
| Protein Purity Assay | >97% |
| RNase Contamination Assay* | Not detectable |
| Endonuclease Contamination Assay* | Not detectable |
| DNA contamination (E. coli, mammalian, library) | <10 copies |
| dsDNA Exonuclease Contamination Assay* | <1% released |
| ssDNA Exonuclease Contamination Assay* | <1% released |
| Phosphatase Contamination Assay* | <1% release |
| Unit Assay | Passed |
* As assessed using 50 U of protein input per assay
| SHIPPING AND HANDLING | |
|---|---|
| Shipping conditions | Glycerol-containing versions: Ice packs Glycerol-free versions: Dry Ice |
| Storage | -20°C ± 5°C |
| Shelf life | 12 months |
What differentiates StellarTaq™ DNA Polymerase (DNAP) from wild type Taq DNAP?
What are relevant applications for StellarTaq DNAP?
- Pathogen detection, including infectious diseases
- PCR amplification of DNA fragments (≤5 kb)
- Probe and intercalating dye-based qPCR
- RT-qPCR (also explore StellarScript HT+ Reverse Transcriptase and RNase Inhibitor)
- PCR applications where inhibitors are present
- Fast PCR
- PCR applications where specificity is important
Can StellarTaq DNAP be used for 1-step RT-qPCR?
Yes. Note that because reverse transcriptases can inhibit polymerase activity, 1-step RT-qPCR assays may benefit from higher polymerase concentrations. Our RNase Inhibitor and StellarScript HT+ Reverse Transcriptase are excellent choices for one and two-step RT-qPCR.
What polymerase and exonuclease activity does StellarTaq DNAP possess?
Does StellarTaq DNAP have hot start functionality?
What method of hot start is used with StellarTaq DNAP?
StellarTaq DNAP uses an antibody to enable hot start functionality.
Does the hot start functionality inhibit the 5' → 3' exonuclease activity as well as the 5' → 3' polymerase activity?
What ends will my PCR products have?
Can StellarTaq DNAP amplify uracil-containing templates?
Can StellarTaq DNAP incorporate modified or alternative bases?
Does StellarTaq DNAP exhibit strand displacement activity?
No. Any strand displacement activity is likely to be far exceeded by its 5' → 3' exonuclease activity that will digest any downstream strand encountered during polymerization.
Is StellarTaq DNAP provided in a glycerol-free format?
How many freeze/thaw cycles can glycerol-free StellarTaq DNAP tolerate?
StellarTaq DNAP is guaranteed to be stable up to 5 freeze/thaw cycles. However, repeated freeze-thaw cycles should be avoided if possible.
What is the storage buffer for StellarTaq DNAP?
- Glycerol-containing: 50 mM Tris-HCl, pH 7.5, 100 mM KCl, 0.1 mM EDTA, 50% Glycerol, 0.05% Tween 20
- Glycerol-free: 50 mM Tris-HCl, pH 7.5, 300 mM KCl, 0.05% Tween 20
What is the recommended reaction buffer for StellarTaq DNAP?
A standard 10X reaction buffer (not supplied with kit) is recommended:
- 200 mM Tris-HCl, pH 8.3, 1000 mM KCl, 0.04% Tween 20
- Additional optimization is likely required. See technical guide for more information
Can I use the same reaction buffer as for wild type Taq DNAP?
No. StellarTaq DNAP performs well in a range of buffers, but requires higher salt concentrations than wild type Taq DNAP to perform optimally. The composition of the recommended 10X buffer (not supplied with kit) is a standard PCR buffer, tailored for the optimal salt concentration of StellarTaq DNAP(1000 mM KCl).
This buffer will need to be optimized for specific applications. Please reference our technical guide for optimization instructions.
What StellarTaq DNAP concentration should I use?
A good general purpose starting point is 0.012 U/μL of polymerase in the reaction. We recommend using higher concentrations (up to 0.12 U/μL) in reactions with high concentrations of inhibitors, for fast PCR, or when no amplification is observed at 0.012 U/μL.
We recommend using lower concentrations of StellarTaq DNAP if non-specific amplification is observed.
What final MgCl₂ concentration should I use?
We suggest using 2 mM MgCl₂ in the reaction. Mg²+ concentrations can alter reaction performance and may need to be optimized. Probe-based qPCR applications will benefit from increased MgCl₂ concentration. A scouting range between 1.5 – 6 mM MgCl₂ is recommended.
Are protected primers required for StellarTaq-based PCR amplification?
How can I maximize the yield from StellarTaq DNAP?
- Set up an initial salt concentration vs enzyme concentration matrix experiment to identify the optimal salt and enzyme concentration.
- Find the optimal magnesium concentration by performing a magnesium titration between 1.5 mM – 6 mM MgCl₂.
- Use templates shorter than 5 kb.
- Optimize annealing temperature of the primers.
- Optimize combined annealing and extension time to minimize non-specific amplification. Note that longer annealing and extension times can result in increased non-specific product formation.
Please reference our technical guide for additional details.
What is the amplification speed of StellarTaq DNAP?
StellarTaq DNA Polymerase can amplify up to 2 kb DNA in 10 seconds.
Do you offer custom formats?
Yes! Watchmaker offers customer fills, packaging, concentrations, and labeling – including private label – designed to meet your unique needs. We offer flexible terms to serve organizations of any size, and our right-sized processes enable rapid turnaround time on customization. Please contact sales@watchmakergenomics.com to learn more about our capabilities.
Are you ISO 13485-certified?
Yes! Our Quality Management System has achieved ISO 13485:2016 Certification. Our certificate has been awarded for the design, development, manufacture, contract manufacture, and support of high performing reagents for genomics applications in medical research. Download the certificate here.
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| Description | 0.25 kU | 1 kU | 7.5 kU | 7 kU | |
|---|---|---|---|---|---|
| StellarTaq Hot Start DNA Polymerase (5 U/μL) | 7K0117-50UL | 7K0117-200UL | Request a quote | ||
| StellarTaq Hot Start DNA Polymerase (30 U/μL) Glycerol-free | 7K0121-50UL | Request a quote | |||
| StellarTaq Hot Start DNA Polymerase (140 U/μL) Glycerol-free | 7K0120-50UL | Request a quote | |||
| StellarTaq DNA Polymerase (5 U/μL) | 7K0116-50UL | 7K0116-200UL | Request a quote | ||
| StellarTaq DNA Polymerase (140 U/μL) Glycerol-free | 7K0118-50UL | Request a quote |
Please contact sales@watchmakergenomics.com to inquire about custom kit configurations.
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Custom Genomic Solutions
Custom formats, white label kitting, single-lot shipments, custom certificates of analysis, advanced change notification, and flexible terms for any size organization...
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- All aspects of our customization process are designed to serve you with speed, agility, and above all else, a commitment to quality
- Tailored fill volumes, labeling (including white and private label), and packaging designed to your specifications
- All products are manufactured within an ISO 13485:2016-certified QMS (download our certificate)
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