Two-Tailed PCRSensitive Short RNA Quantification with Two-Tailed RT-qPCR
Quantify miRNA, siRNA, CRISPR/Cas9 single guide RNA (gRNA) and other challenging short nucleic acid targets with tailored Two-Tailed RT-qPCR assays. Developed in our Gothenburg laboratory, this specialized approach enables short-target analysis using qPCR or dPCR readouts, with method development and validation matched to your research or drug development needs.
Developed in our Gothenburg laboratory.
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Comparison
qPCR vs dPCR vs Two-Tailed PCR: Which PCR approach is the best fit for your project?
The most useful starting point is the molecule you need to measure. Conventional qPCR and dPCR are readout technologies; Two-Tailed PCR is a specialized target-preparation and assay-design strategy for sequences that are too short for straightforward conventional PCR primer placement.
| Choose this service | When your project needs it |
|---|---|
| qPCR services | Routine or custom quantitative PCR assays for suitable DNA/cDNA targets, including relative gene expression and standard-curve-based quantification. |
| dPCR services | Partition-based absolute quantification, copy-number measurements or selected low-abundance targets where a digital readout adds value. |
| Two-Tailed PCR / Short RNA services | A tailored reverse-transcription strategy for very short RNA targets such as miRNA, siRNA or gRNA, followed by an appropriate qPCR or dPCR measurement. |
Not sure which approach to use? Share your target sequence, matrix and analytical objective, and our scientists can help select a suitable method. Book your consultation here!
About Two-Tailed PCR
Short RNA Analysis at SCD
Short regulatory RNAs and therapeutic oligonucleotides can be difficult to quantify with standard PCR designs. Their limited sequence length leaves little room for the conventional two primers binding, while chemical modifications, closely related sequences and biological sample matrices can complicate extraction and detection.
SCD offers a dedicated short nucleic acid bioanalysis service built around Two-Tailed PCR, a technology developed by the team formerly known as TATAA Biocenter. From our Gothenburg, Sweden laboratories, we support assay feasibility, optimization, qualification, validation and sample analysis. This capability complements SCD’s broader molecular profiling and discovery services.
Specifications
Short RNA PCR Specifications
| Specification | Service information |
|---|---|
| Specialized method | Two-Tailed Reverse-Transcription PCR for short RNA targets |
| Target classes | miRNA, siRNA, guide RNA,, ASOs and other short oligonucleotides assessed case by case |
| Measurement options | qPCR or dPCR |
| Sample materials | Tissue, blood and liquid-biopsy matrices; fresh-frozen and FFPE materials; specimens collected in EDTA or PAXgene systems, where compatible |
| Assay customization | Target-specific primer design, optimization and feasibility evaluation |
| Analytical studies | Feasibility, method development, qualification and validation according to intended use |
| Potential performance assessments | Specificity, selectivity, extraction recovery, precision, accuracy, quantifiable range, dilution effects and stability as appropriate |
| Quality framework | Research workflows and applicable GLP/GCLP work; exact accredited scope to be confirmed |
| Deliverables | Target measurement data, QC findings and agreed method/validation documentation |
| Instrumentation / capacity | qPCR/dPCR platform, sample volume and throughput confirmed during project planning |
Design Flexibility
Why Two-Tailed PCR for Short RNA Targets?
A conventional PCR assay typically needs two primer-binding regions surrounding its target. For molecules only a few nucleotides longer than the primers themselves, that arrangement may not be feasible. Two-Tailed PCR addresses this problem at the Reverse-Transcription stage by elongating the sequence using a Reverse-Transcription primer with a hairpin sequence.
Besides the hairpin, the RT primer carries two hemiprobes, which are target-recognition segments. Their combined interaction with the target short RNA supports sequence recognition while the reverse-transcriptase creates an extended cDNA product. That longer cDNA product can subsequently be measured using PCR.
An important practical benefit is design flexibility: the two target-interacting regions can be adjusted during assay optimization. This may help scientists discriminate related short sequences and adapt an assay to demanding performance requirements. Actual specificity and sensitivity must still be established experimentally for each target.
How does Two-Tailed PCR work?
The Two-Tailed PCR
1. Primer Design
A hairpin primer with two target-specific hemiprobes enables precise detection.
2. Specificity
Cooperative binding enhances specificity.
3. Target Elongation
Reverse transcriptase elongates the target, making it compatible with standard PCR amplification.
4. PCR Bioanalysis
Quantification with standard qPCR or dPCR.
two-tailed pcr workflow
From Study Question to Quantitative Results
Step 1
1. Define the short nucleic acid target
We review target length, sequence, modifications, expected abundance and potential closely related molecules. The required biological matrix and study objective shape the assay strategy.
Step 2
2. Design the two-recognition-region primer
A hairpin Reverse-Transcription primer is designed with two target-specific segments. Candidate designs are evaluated for binding behavior and compatibility with downstream detection.
Step 3
3. Extend the target during reverse transcription
The primer binds the short RNA, allowing reverse transcriptase to generate a longer cDNA product suitable for amplification.
Step 4
4. Quantify by qPCR or dPCR
The resulting cDNA is measured using an appropriate quantitative or digital PCR readout, selected according to the required concentration range, precision and reporting format.
Step 5
5. Review controls and report results
Analytical controls and predefined criteria are used to assess the reliability of each run. Results are delivered with the agreed interpretation and documentation.
Applications
Applications of Two-Tailed RT-qPCR in Research and Drug Development
- miRNA biomarker studies: measure selected microRNAs in tissues or biofluids to investigate disease-associated or treatment-related changes.
- siRNA therapeutics: develop targeted methods to track short interfering RNA molecules in relevant matrices, including pharmacokinetic or biodistribution studies where appropriate.
- Guide RNA analysis: evaluate selected gRNA targets used in genome-editing research and advanced therapy development.
- Antisense oligonucleotides: assess whether a tailored assay can quantify the specific ASO chemistry and target sequence; modified oligonucleotides may need additional feasibility work.
- Short viral RNA: measure suitable short viral sequences using a target-specific assay.
- Liquid-biopsy and circulating RNA research: investigate low-abundance short RNA markers while accounting for collection, extraction and normalization effects.
Assay development
Assay Development, Qualification & Validation
Short RNA bioanalysis is not a one-size-fits-all workflow. Target chemistry, sequence similarity, extraction recovery and biological matrix can all influence the measurement. Our team establishes an assay strategy appropriate to the decision the data must support, whether exploratory screening or a more formally controlled study.
- Feasibility: assess candidate primer designs, expected target detection, amplification behavior and the practicality of the selected sample matrix.
- Method development: optimize extraction, reverse transcription, assay conditions, quantification range and controls.
- Qualification: document fit-for-purpose performance for the intended study context.
- Validation: assess defined characteristics such as precision, accuracy, selectivity, specificity, recovery, dilution effects and stability, where applicable, under an agreed protocol.
Need a fully developed or validated molecular assay? Explore Method Development & Validation.
Quality control
Quality Controls for Small RNA Measurements
Small RNA assays are particularly sensitive to pre-analytical variation. Collection tubes, processing time, degradation, matrix composition and extraction chemistry may alter the amount of measurable target before PCR begins. Chemically modified oligonucleotides can also behave differently from unmodified RNA.
We therefore consider process controls, suitable negative and positive controls, extraction-recovery experiments, reverse-transcription performance, matrix effects and quantitative reference materials as appropriate. For qualified or validated methods, QC samples and acceptance limits are defined in advance and evaluated against the relevant protocol.
Controls must be selected for the actual assay and matrix. A successful PCR amplification alone does not establish that the entire extraction-to-result workflow is reliable.
Comparison
Two-Tailed PCR vs. Stem-Loop RT-PCR
| Two-Tailed PCR | Conventional stem-loop RT-PCR |
|---|---|
| Two target-recognition segments offer additional design variables for optimization. | A stem-loop RT primer generally binds a short region at the target’s 3′ end, with fewer design options. |
| May be helpful where closely related sequences or assay validation requirements make optimization difficult. | Can be an effective and practical option when it meets the needed specificity, sensitivity and robustness. |
| Performance must be demonstrated for each assay and matrix. | Performance likewise depends on experimental verification and sample handling. |
Neither approach is automatically superior for every sequence. SCD evaluates assay suitability against the biological target and required analytical performance.
Our expertise
Specialized Short RNA Expertise in Gothenburg
Formerly TATAA Biocenter
Two-Tailed PCR was developed by the scientists of TATAA Biocenter, now TATAA, an SCD company. The same specialist molecular biology expertise continues at SCD’s Gothenburg laboratory, where the team supports short RNA measurement and assay development for research and drug development.
This service draws on peer-reviewed Two-Tailed RT-qPCR research, including a 2017 methodological publication and a 2019 study applying a Two-Tailed panel to circulating microRNA quality control. Combined with SCD’s discovery capabilities in the Netherlands, this provides a route from broad molecular profiling to focused measurement of selected short RNA targets.
Why work with SCD? You can discuss assay feasibility directly with experienced scientists, select an appropriate PCR readout, and access complementary RNA/DNA extraction and molecular validation services within the same organization. Applicable regulatory and accreditation details are confirmed before study initiation. You can discuss your research question with us here.
2
Target-recognition regions
Two hemiprobes in the specialized reverse-transcription primer
3
Assay designs per target
Specified in TATAA's published service characterization workflow
2017
Original method publication
Two-Tailed RT-qPCR described in Nucleic Acids Research
2019
Published biofluid QC application
Two-Tailed RT-qPCR panel reported in Scientific Reports
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What our clients say
"The service of Single Cell Discoveries guarantees a smooth process between customer and company. In case of problems or questions, the scientists reacted competently and immediately, so that answers could be found quickly and flexibly."
"Fantastic job made by a really professional and friendly team. I strongly recommend Single Cell Discoveries for sequencing services."
Recent publications using Two-Tailed PCR
bioRxiv
A Double-Negative Prostate Cancer Subtype is Vulnerable to SWI/SNF-Targeting Degrader Molecules
bioRxiv
SP140 limits type I interferon-driven pathology, preserving T cell motility and promoting resistance in tuberculosis
Nature Communications
Targeted CRISPR-Cas9 screening identifies core transcription factors controlling murine haemato-endothelial fate commitment
npj Precision Oncology
A single-cell atlas reveals the tumorigenesis and microenvironment status of primary tracheobronchial tumors
Nature Cardiovascular Research
Oxidative phosphorylation is required for cardiomyocyte re-differentiation and long-term fish heart regeneration
Research Square
GPR124/WNT signaling regulates hyaloid blood vessel regression and endothelial-mesenchymal transition
Case studies
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Immune Profiling of atherosclerosis reveals new therapeutic potential
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Mechanism of disease: a new hypothesis for atherosclerosis
To elucidate atherosclerosis’ mechanism of disease, Sheffield University researchers analyzed the transcriptomes of single endothelial cells.
Recent blogs related to Two-Tailed PCR
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Frequently Asked Questions
Two-Tailed PCR is a specialized reverse-transcription assay strategy for measuring short RNA targets. A hairpin primer with two target-recognition segments enables the short target to be converted into an extended cDNA product that can be quantified by PCR.
Mature miRNAs are typically only about 20–24 nucleotides long. Their limited length makes it difficult to place the two conventional primers needed for direct PCR amplification. A specialized reverse-transcription design provides the additional sequence needed for measurement.
The approach is relevant to several short nucleic acid classes, but suitability depends on sequence, chemical modifications and target chemistry. For ASOs in particular, assay feasibility should be established before promising a validated quantitative method.
No. Two-Tailed PCR prepares and selectively recognizes a short target so that a PCR readout becomes possible. qPCR and dPCR are alternative ways to quantify the resulting assay signal.
Both approaches use reverse transcription to make short RNA targets measurable. Two-Tailed designs use two target-recognition regions, creating additional opportunities for assay optimization; conventional stem-loop primers commonly rely on one short target-binding segment.
The dual-recognition design can help optimize specificity, but discrimination of closely related sequences or single-nucleotide differences must be demonstrated with relevant cross-reactivity experiments.
Potential matrices include tissues, blood, liquid biopsies, fresh-frozen material and FFPE specimens. Compatibility depends on sample collection, storage, extraction requirements and the target being measured.
Some modified short nucleic acids may be measurable, but chemical modifications can affect extraction and reverse transcription. Our team evaluates each test item’s chemistry and expected performance during feasibility assessment.
Yes, where the assay and sample matrix are suitable. Quantification of selected short RNA therapeutics can support studies of tissue distribution or concentration over time, subject to study-specific validation requirements.
SCD has molecular bioanalysis capabilities in Gothenburg that can support work under appropriate quality frameworks. Whether a particular study falls within the applicable GLP/GCLP and accredited scope must be confirmed during project scoping.
Depending on intended use, evaluation may cover selectivity, specificity, precision, accuracy, extraction recovery, quantifiable range, dilution behavior, stability and relevant controls. The validation plan and acceptance criteria are agreed for the study.
Input requirements vary by matrix, target abundance, extraction method and whether qPCR or dPCR is used. Share the available volume or tissue amount so the team can assess feasibility and material requirements.
It may be suitable for targeted follow-up of selected short RNA candidates identified through an appropriate small-RNA profiling workflow. The chosen sequencing method must actually capture the relevant short RNA class.
Provide the target name or sequence, nucleic acid class, any chemical modifications, sample type, sample count, expected abundance if known, study purpose, timeline and required quality or regulatory framework.
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Discuss Your Short RNA Project
Need to quantify a microRNA biomarker, measure an oligonucleotide therapeutic or establish a fit-for-purpose assay for a difficult short target? Share your target, matrix and study objectives with our scientists. We will help assess the analytical approach and the next steps.