# Early Infection for Mass Production of Artificial Single-Stranded DNA with _Escherichia coli_
## 5 Conclusions  
We have shown in this study how infection material can be efficiently reduced in the mass production of artificial single-stranded DNA by early infection. The reduction in infecting particles by a factor of 250,000 enables the scalability of ssDNA production to industrial scales. As a promising example of ssDNA applications in the future, nanotechnology-based virus capture traps using ssDNA as a building block may act as a drug platform to combat the majority of acute viral infections and respond to emerging viral threats like SARS-CoV-2 [40]. Examples of successful neutralization with DNA origami nano shells have been reported for a wide range of viruses. These nano shells can be specifically functionalized with antibodies targeting a particular virus, even when the individual binders exhibit little-to-no antiviral effectiveness [3]. Alternatively, they can be functionalized with nonspecific binders, such as heparan sulfate proteoglycans, which rely on avidity and a broad background affinity for their effectiveness. The trapping mechanism can prevent viruses from further interactions with receptors [11]. For these and other applications, a scalable method for the production of ssDNA is essential. A potential downstream protocol for the purification of ssDNA after the biotechnological production of ssDNA packed in phagemid particles comprises cell removal, polyethylene glycol-mediated phagemid precipitation, chemically phagemid lysis, and ssDNA precipitation with ethanol [25]. Even if precipitation is a scalable downstream method, ssDNA purification from the fermentation broth does not yield sufficient purity. Ongoing research work focuses on providing endotoxin-free ssDNA as the basis for therapeutic applications. **Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app142311459/s1](https://www.mdpi.com/article/10.3390/app142311459/s1)]([https://www.mdpi.com/article/10.3390/app142311459/s1](https://www.mdpi.com/article/10.3390/app142311459/s1)), Figure S1: Plasmid map of the phagemid CSF1_4843; Figure S2: Plasmid map of the phagemid CSF1_6106; Figure S3: TEM field view of the folded DNA origami from the isolated ssDNA from the high cell density cultivation of _Escherichia coli_ JM109 pfhp30 infected with CSF1_4843 phagemid particles in a 25 L stirred tank bioreactor DNA origamis were PEG-purified before imaging. ; Figure S4: TEM field view of the folded DNA origami from the isolated ssDNA from the high cell density cultivation of _Escherichia coli_ JM109 pfhp30 infected with CSF1_6106 phagemid particles in a 25 L stirred tank bioreactor DNA origamis were PEG-purified before imaging. ; Figure S5: TEM field view of the folded DNA origami from the isolated ssDNA from the high cell density cultivation of _Escherichia coli_ JM109 pfhp30 infected with CSF1_6106 phagemid particles in a 1000 L stirred tank bioreactor DNA origamis were PEG-purified before imaging; Figure S6: Agarose gel electrophoresis of the scaffolds and the respective 42-helix bundles (a) CSF1_4843 on a 25 L scale in Figure 3. (b) CSF1_6106 production on a 25 L in Figure 3. (c) CSF1_6106 production on a 1000 L scale in Figure 4.; Figure S7: Design diagram of the 42 helix bundle DNA origami structure used for quality control of CSF1_4843 ssDNA; Figure S8: Design diagram of the 42 helix bundle DNA origami structure used for quality control of CSF1_6106 ssDNA; Table S1: Composition of 50 x trace element solution; Table S2: Full list of oligonucleotides used for folding the 42 helix bundle DNA origami structure with CSF1_4843 as scaffold. ; Table S3: Full list of oligonucleotides used for folding the 42 helix bundle DNA origami structure with CSF1_6106 as scaffold. **Author Contributions:** Conceptualization, N.H., H.D. and D.W-B. ; methodology, validation, formal analysis, and investigation, N.H., N.N.S. and M.N.H. ; writing--original draft preparation, N.H. and M.N.H. ; writing--review and editing, D.W.-B., M.N.H. and H.D. ; visualization, N.H.; supervision, D.W.-B.