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- Services
- Custom Circular Single-Stranded DNA Synthesis
OVERVIEW
Reliable and customizable CssDNA for rolling circle amplification, biosensing, DNA nanotechnology, molecular probes, and exploratory gene regulation research.From sequence review and splint design to circularization, purification, and quality control, Gene Universal provides an integrated service tailored to your research requirements.
16–120 nt
Standard Lengths
Custom Lengths
Available upon feasibility review
10–100 µg
Delivery Options
≥90%
CE Purity
7–15 days
Estimated Turnaround
What Is Circular Single-Stranded DNA?
Circular single-stranded DNA, or CssDNA, is a covalently closed DNA molecule consisting of one continuous single strand with no free 5′ or 3′ ends.
Compared with the corresponding linear ssDNA, its closed topology can provide enhanced resistance to exonuclease-mediated degradation. Its sequence programmability also makes CssDNA a versatile scaffold for amplification, sensing, nanotechnology, and nucleic acid research.
Circular ssDNA
No free 5' or 3' endsEnhanced resistance toexonuclease degradation
Linear ssDNA
Free 5' or 3' endsMore susceptible toexonuclease degradation
Applications of CssDNA
Rolling Circle Amplification
Serve as a template for RCA to generate long repetitive DNA products for signal amplification and assay development.
Molecular Probes & Biosensors
Support nucleic acid detection, mutation analysis, molecular diagnostics research, and signal-amplification workflows.
DNA Nanotechnology
Incorporated into self-assembled DNA structures, DNA origami, molecular devices, and nanoscale materials.
Aptamer & Delivery Research
Programmable scaffold for aptamer development, ligand conjugation, and DNA nanostructure-based delivery studies.
Gene Regulation Research
Explore as antisense or miRNA-inhibitory scaffolds and as programmable vectors in selected cellular or cell-free systems.
Gene Editing Research
Evaluate as a customizable donor or nucleic acid scaffold in exploratory genome-editing workflows.
Synthetic Biology
Support the development of molecular circuits, functional nucleic acids, and engineered biological systems.
Service Workflow
1 
Sequence & Splint Design
A complementary splint is designed to bring the 5′ and 3′ ends of the target ssDNA into close proximity.
- 2
End Preparation
The target oligonucleotide is prepared with the appropriate 5′-phosphate and 3′-hydroxyl termini.
- 3
Enzymatic Circularization
T4 DNA ligase catalyzes the formation of a phosphodiester bond between the juxtaposed termini.
- 4
Removal of Linear Species
Nuclease treatment and purification procedures are used to deplete residual linear and other non-circularized species.
- 5
Quality Control & Delivery
The purified CssDNA is evaluated using project-appropriate analytical methods before release.
Specifications
| Standard length | 16–120 nt |
| Custom length | >120 nt, subject to feasibility review |
| Delivery amount | 10, 20, 50 or 100 µg |
| Standard Purity | ≥90% by CE |
| Estimated turnaround | 7–15 days |
| Deliverables | Purified CssDNA and QC report |
Final feasibility and turnaround time depend on sequence length, sequence complexity, delivery quantity, secondary structure, and QC requirements.
Quality Control
| Standard QC | Optional QC |
|---|---|
| Visual Inspection | Concentration by Qubit |
| Circularity Assessment | Residual Template DNA by qPCR* |
| Concentration by NanoDrop | Residual Protein Analysis |
| A260/A280 Ratio | Residual Nuclease Activity |
| CE Purity Analysis | Endotoxin Testing |
| RCA + Sanger Sequencing* | Bioburden testing |
| QC Report | Mass Spectrometry* |
| *Where technically applicable. | Custom Analytical Methods |
| *Where technically applicable. |
Case Study
Mass Spectrometry Confirmation of DNA Circularization
T5 Exonuclease Challenge of Linear and Circular ssDNA
Under the tested conditions, the circularized products showed greater resistance to T5 exonuclease treatment than the corresponding linear ssDNA controls.
Nuclease Challenge Analysis of 900 nt CssDNA
Agarose gel electrophoresis of 900 nt CssDNA samples before and after nuclease treatment and RCA.
CssDNA Purity Analysis Results
Why Choose Gene Universal?
End-to-End Customization
Integrated support covering sequence review, splint design, synthesis, circularization, purification, and analytical testing.
Flexible Lengths and Scales
Multiple delivery quantities are available, with customized solutions for longer or structurally complex sequences.
Comprehensive Quality Control
Standard and optional QC methods can be selected according to your downstream application.
Application-Oriented Support
Our technical team evaluates sequence features, project objectives, and downstream workflows before production.
Clear Project Documentation
Each project is delivered with the corresponding analytical results and QC report.
Ready to Start Your CssDNA Project?
Send us your target sequence, required quantity, intended application, and QC requirements. Our technical team will review project feasibility and prepare a customized quotation. For Research Use Only. Not for use in diagnostic or therapeutic procedures.
Online Request Submission
Have a question about sales or support? Our team is ready to help!