Circular Single-Stranded DNA
Circular single-stranded DNA (cssDNA), also known as single-stranded plasmid DNA, is a DNA molecule characterized by its closed-loop structure. Unlike conventional linear DNA, cssDNA features covalently linked 5′ and 3′ ends, forming a continuous, stable circular structure.
At BiOligo, we leverage years of expertise in oligonucleotide synthesis. We have established a proprietary High-Precision Solid-Phase Synthesis Platform and an Optimized Circularization Technology that together enable the efficient synthesis of high-quality cssDNA.
Features
Patented Circularization Technology- We employ a two-step end-modification and ligation strategy to achieve > 95% cyclization efficiency, drastically minimizing linear DNA impurities.
Precise Sequence Control
- Our proprietary sequence design system optimizes synthesis for challenging sequences (including GC-rich and repetitive regions), ensuring sequence accuracy above 99.9%.
Fully Customizable Options
- We support over 200 modifications and offer secondary structure prediction analysis, allowing us to meet your diverse and personalized research needs.
Rigorous Quality Control (QC)
- Utilizing proprietary purification processes, we guarantee a purity of 95%. Mass Spectrometry and HPLC thoroughly validate each batch, and a complete QC report is provided.
Fast Turnaround
- Our streamlined production and quality assurance processes ensure the rapid delivery of your customized cssDNA products.
| Base Length | Lead Time |
| 15-50 nt | ≤ 7 BD |
| 50-105 nt | ≤ 10 BD |
| 106 nt | Inquire |
Cases
Example: Synthesis of 20 nt, 30 nt, and 50 nt Circular Single-Stranded DNA
In this example, single-stranded DNA fragments of 20 nt, 30 nt, and 50 nt were synthesized and circularized by covalently joining the 5′ phosphate and 3′ hydroxyl termini to form a stable circular structure.
(1) Mass Spectrometry (MS): Confirms the expected molecular weight of the circularized DNA.
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20 nt single-stranded linear DNA
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20 nt circular single-stranded DNA
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30 nt single-stranded linear DNA
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30 nt circular single-stranded DNA
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50 nt single-stranded linear DNA
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50 nt circular single-stranded DNA
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The target molecular weight shows a decrease of approximately 18 Da after circularization, consistent with the characteristic change observed when linear ssDNA forms a circular structure. During the cyclization process, one molecule of H2O is released, resulting in an 18 Da reduction in molecular weight.
(2) High-Performance Liquid Chromatography (HPLC): Demonstrates high product purity and minimal linear DNA residues.
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20 nt circular single-stranded DNA, purity: 98.95%
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30 nt circular single-stranded DNA, purity: 98.99%
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50 nt circular single-stranded DNA, purity: 99.00%
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BiOligo offers customized synthesis of short circular single-stranded DNA, delivering structural stability, precision synthesis, and tailored design. We support research institutions, diagnostic developers, and pharmaceutical companies with reliable, high-performance nucleic acid tools.
